Alastair Shephard

Content Writer

Alastair Shephard | Author

Joseph Law

Bumper Content Writer

Joseph Law | Author

It's easy to forget car maintenance, especially regarding oil changes. We jump in and drive every day, expecting everything to run well. But you need to keep on top of maintenance for a healthy car.

Today, we're explaining what happens if you don't change your oil and how long you can go without an oil change. Let's get into it!

What happens if you don’t change your oil? 

You will face many issues if you don’t change your engine oil. These include increased wear, worse MPG, overheating, increased emissions, clogged systems, voided warranty, decreased resale value, and potential engine failures. 

So, there’s nothing positive to be gained from putting your oil change off.

The oil in your engine reduces friction and heat by lubricating the moving parts. When the oil is fresh, it lubricates at peak efficiency and minimises wear on the engine components.

When the oil breaks down, the two faces will wear significantly faster. This will be hard to notice on the camshafts, but over time, this increased wear on the cylinder bores will create a significant loss in power.

Here are the eight problems you’ll encounter if you don’t change your oil frequently. 

Not only does oil lubricate, but it also plays a crucial role in cooling down certain parts of the engine. Race cars often have dedicated oil coolers, but many run-of-the-mill cars also implement designs to reduce oil temperature. 

Surpassing oil change intervals can lead to a reduction in oil-based cooling and excessive heat from increased friction. 

Both symptoms are not good for an engine, and more heat generally equates to less efficiency, more wear and a higher chance of something breaking permanently.

. As a consequence of the increase in heat, reduction in compression due to worn cylinders and a lack of cooling, fuel efficiency will likely decrease. 

Over time, this could significantly increase fuel costs, probably more so than the cost of an oil change!

A decrease in fuel efficiency generally coincides with an increase in harmful emissions, mainly by burning oil due to excessive engine wear. 

A small amount of engine oil will always make its way into the engine's combustion chamber, but the more wear to the cylinder walls, the more will enter and burn off as nasty emissions. 

4. Systems will clog with dirt and debris 

Many complex mechanisms rely on good oil flow to function properly. Examples include variable valve timing, turbochargers and engine breathers.

VVT or Vanos systems often use the engine's oil pressure to operate. These are extremely precise systems, and any oil pressure, quality, or viscosity decrease can affect them. In the best case, the engine stops varying the valve timing properly. 

In the worst case, the Vanos system clogs and requires removal, replacement, or cleaning.

5. Turbos can fail and destroy your engine 

Extremely common in modern cars, turbochargers utilise waste energy from the exhaust to increase power and efficiency. Turbos are responsible for the modern spate of small, high MPG-achieving engines such as those found in Ford, Audi and Volkswagen vehicles. 

Turbos spin incredibly fast, more than 10,000 RPM. To turn efficiently, they need a substantial supply of oil; a partial or momentary pause in the oil supply can cause the turbine to overheat and fail.

Because half of the turbo is in the path of air entering the engine, if shards of the turbine break off due to catastrophic failure, they can quickly enter the engine, causing severe damage. 

If you’ve ever waited a long time between oil changes, you probably noticed a difference in how well the car performed after the oil change was complete. Simply put, with fresh new oil, your engine’s spinning parts can move smoothly and use less power to make their revolutions. 

The manufacturer’s warranty for a new car can last as long as a decade — if you stick to its prescribed maintenance schedule. Skip too many oil changes, and the warranty terms might render it void. 

If there’s ever a major repair, it could cost you thousands more than it would have if the warranty was still valid. 

Resale value probably isn't the first thing on your mind when you buy a car. Eventually, however, the day comes when you want to sell or trade-in your vehicle for a new one. 

Keeping to a schedule of regular oil changes will increase your car's resale value. The engine will perform noticeably better on inspection or in a test drive. Keep a detailed record of oil changes and other regular maintenance; you might even improve your sale price. 

What are the benefits of changing your oil on schedule? 

Keeping your engine healthy with fresh oil has many benefits, including preventing engine failure, reducing engine wear, increasing resale value, and improving your car maintenance. 

When you have an oil change done, it allows the mechanic to visually inspect your car under the bonnet. They'll see the battery, air filters, brakes, and whatever else they have on their standard list. That means they'll be able to note any potential problems before they happen. 

Every car has a suggested manufacturer’s maintenance schedule for regular servicing. Focusing on oil changes makes it easier to track the intervals and ensure you’re being seen by a mechanic at least once a year. 

Your mechanic will probably remind you about any upcoming scheduled maintenance in addition to the oil change so you can book an appointment on the spot. 

If your engine oil turns to sludge, it won't be able to lubricate anymore, and your car engine will seize up. That means the metal parts fuse under intense friction and heat. It's almost impossible to fix, probably requiring a new engine or even a write-off of the car.

Does missing oil changes cause engine wear? 

Yes, oil prevents wear by minimising the friction between the engine's moving parts. Oil also has a limited service life, meaning it breaks down and stops providing the same level of lubrication, leading to rapid wear. 

Almost anyone can do an oil change. The tools needed to change your car’s oil are not complex or expensive, but it does need to be done safely, as it usually requires jacking up the vehicle and crawling under the engine.

If you don’t want to change it yourself, you should be able to easily 

 for an oil change near you. Almost any garage can offer oil changes as it is one of the most basic tasks a mechanic can do. 

Split the cost of repairs into interest-free monthly repayments and choose from thousands of service partners nationwide.

As one of the most essential car service elements, oil changes are always included in 

. This generally also consists of an oil filter change to keep the new oil cleaner for longer.

It’s good practice to check what oil grade and quality the garage will be using, especially if you’re not taking your car to a primary dealer for servicing. We have a handy 

Whilst things like engine oil leaks would be noticed, the MOT test does not include an oil level or quality check, or an oil change. For this reason, booking a service at the same time as an MOT test is a good idea. 

An annual MOT test is a legal requirement for cars over three years old. The test includes checking all safety critical systems such as brakes, suspension, and tyres. 

Check out our guide here for more on precisely what an MOT covers

How long can you go without an oil change? 

Experts suggest you should change your car’s oil every 3,000 miles. 

But this doesn’t apply to all modern cars. Instead, you should check your owner’s manual. This will give you specific information, and you won’t have to rely on vague estimates.

Historically, oil changes were determined by how many miles you’d driven since the last change. Today, we can use three key factors to estimate when you need to change your oil. These include:

You must look at vehicle type, as some require different oil change times than others. Similarly, the length of your average drive will affect your oil changes. Short trips and inner-city drives are more demanding on your engine and require more oil changes.

Finally, older cars generally require more maintenance and oil changes than newer cars. So, if you’ve just bought a new car, you won’t have to change your oil as often as older ones.

Is it okay to go a year without an oil change? 

Put simply, no. The oil should be changed for most cars every 3-6,000 miles. For most cars, not changing your oil for over a year means missing two separate changes, which could seriously damage your engine.

Making time for something as mundane as an oil change is an annoyance, but it's vital to your car's health. If you want your car to last a long time and perform well, take the time to get the oil changed. Expect to spend more if you don't.

What are the signs that suggest an oil change? 

Over time, the engine will exhibit signs that you need an oil change, like increased fuel consumption, reduced performance, and smoky exhaust fumes.

Other signs you need an oil change include:

The danger appears because unlike knocking suspension or a blowing exhaust, not changing the oil does not make a loud or easily noticeable difference, at least for the first few months. 

However, once these symptoms start to show, it may well mean your engine is seriously damaged already - so follow those service intervals!

How many miles can you go over an oil change sticker? 

You might find a sticker inside your engine bay that states a mileage. These are often used to record when an oil change was last done. It's best to limit the miles past the sticker as much as possible, even having the oil change done in advance.

The trouble with oil change stickers is that they might not be 100% accurate, as there is no way to officiate the work.

We generally recommend using your car's service book. That way, there can be no confusion over what was done and by whom. The book can also be passed to a prospective buyer, giving a detailed car history.

What happens if you don't change your oil for 10,000 miles? 

Some manufacturers now recommend an oil change every 12-15,000 miles, so it may well be that 10,000 is fine. But as the previous point, it's best to check your owner's manual alongside the service records for peace of mind. 

What happens if you don’t change your oil - The bottom line 

Staying on top of your oil changes is a guaranteed way to keep your car healthy and prevent avoidable problems. This will make driving safer and save you lots of money in the future. Don’t put it off!

Need an expert opinion? Book your vehicle with a reliable repairer and split the cost into interest-free monthly payments with Bumper 

What Happens If You Don’t Change Your Oil

Since the Euro 5 regulatations that came into effect in 2009, Diesel particulate filters have effectively been mandatory on all new Diesel engined vehicles. 

The main aim of this regulation change was to reduce the amount of harmful pollutants emitted in towns and cities. In this article we’ll delve into what they are, why they’re used and what the drawbacks can be.

As the name suggests, it is a filter that prevents harmful particulates from exiting the engine via the exhaust system. The main particulate it stops is soot, this is a by-product of using diesel fuel. 

A DPF’s job is to trap the soot and hold it until it can be transformed into ash via a process called regeneration, which requires the DPF to be extremely hot. 

The main benefit in buring soot into ash is that the latter is much less harmful to humans, soot stays in the air we breathe for a long time, and makes up most of inner city air pollution.

Inside the unit are a series of filters, these trap the soot and keep it until it burns away. As already mentioned the burning process is known as regeneration, and it requires the filter to be at nearly 500°C. 

As the exhaust only reaches these temperatures at high speeds and engine loads, the ash will typically not burn off until the car is driven at high speeds for an extended period, such as when on the motorway.

This helps to both reduce the amount of soot emitted in and around town, but also to reduce the amount of overall polutants deposited into the air we breathe.

There are two types of regeneration; Active and Passive. Passive regeneration is the type just explained, this happens during normal usage (as long as long journeys are made) and the car’s computer needs not intervene. 

If for any reason the car is not driven at high speeds, for instance through traffic in town, the car's ECU (Electronic Control Unit) will detect that the DPF has not regenerated for a long time. It will then start an active regeneration cycle.

Active or forced regeneration generally involves the engine altering the fuel/air mixture in order to make the engine produce more heat from the exhaust, this is not very fuel efficient but can help to remove built up soot.

Some cars even use a specialst catalyst solution stored in a tank, that is injected into the DPF to aid the burning of deposited soot.

What is a Blocked Diesel Particulate Filter? 

A common fault with any DPF system is the complete or almost complete blockage of the filter due to excessive soot build up. 

One of the most cited reasons for not choosing a diesel engined car is that they need to be driven long distances, this is in part due to the DPF, another common cause can be the EGR valve.

As already mentioned, the DPF needs to reach temperatures of approximately 500°C in order for the soot to be burnt off. If the vehicle is only driven for short periods of time, the passive regeneration of the DPF will not occur. 

The ECU will inevitably try to force a regeneration, but this can only be completed if the car is at a certain temperature already and will be driven for a certain time after the regeneration has started. This is often not the case within cities and with infrequent use. 

Diesel Particulate Filters are a relatively new addition to the average diesel vehicle in the UK, they have been used in off-road diesel vehicles since 1980, such as forklifts and excavators. HGVs and trains have also used them for many years.

It wasn’t until the new Euro 5 regulations in 2009 that meant all diesel vehicles sold in Europe now required a filter to bring overall emissions down. Many manufacturers added them in advance, The PSA group (Citroen and Peugeot) were the first manufacturer to include DPFs as standard.

This means if your diesel car was sold after 2009, it will almost certainly have a DPF. Many cars prior to 2009 will do as well though, as manufacturers modified their designs to comply in advance.

The best way to check is to look in your owner’s handbook for reference to DPF regeration or similiar.

There are a number of considerations when driving a vehicle with a DPF, to ensure it does not get prematurely clogged and cause issues.

As we discussed in the regeneration section, the exhaust needs to be hot to burn off the soot, if it never reaches a temperature high enough, it will only become more blocked.

To mitigate this, don’t use the car for solely short journeys, or ensure at least once a week it does a journey above 40mph for over 30 minutes, or more if possible.

Special oils have been developed for use in DPF-fitted cars, with a lower content of elements that can cause soot build up, namely Sulphated Ash, Phosphorus and Sulphur.

These are usually labelled as low SAPS, and will be found at any regular shop selling engine oil. For more information about oils, 

Take care of any other engine issues promptly 

Diesels are generally more complex than petrol engines, and have various components that can fail and cause issues with DPFs.

You should pay close attention to any issues pertaining to:

All of the above can cause excess oil or soot to exit the engine, either through miss-fueling or oil consumption. These will clog up a DPF in record time, so be on the lookout for dash warning lights and act quickly.

In order to prevent the need for complete DPF replacement, you should be aware of any issues as soon as they arise. Here are the most common symptoms of a blocked DPF:

, it's best to sort it as soon as possible, as it will only get worse. For 

interest free vehicle repairs and servicing

, enter your vehicle registration and postcode on our website.

has been writing about cars for over seven years and writing for Bumper for over two, blending his passion for automobiles with a talent for storytelling.

Joseph has written about engineering and cars for Autozilla, Komaspec, and several engineering manufacturers. When he's not writing or tinkering with one of his five cars, Joseph dreams of owning an Alfa Romeo 33 Stradale.

What is a DPF (Diesel Particulate Filter)?

If you’re in the market for a mid-size luxury SUV, you'll undoubtedly come across both the Range Rover Evoque and the Discovery Sport in your search. Whilst these are a few similarities, the two cars are aimed at slightly different markets. This guide will help you pick between the two.

From the 1970s to the launch of the Evoque, Range Rovers were always full-size SUVs, with the smallest being the Range Rover Sport. In 2011 the Jaguar Land Rover group identified a gap in the market for a smaller car that retains the Range Rover branding and style. 

The Evoque was very popular on release and still is today, 14 years later. It appeals to those looking for the luxury and style of a Range Rover, but who don't need an enormous SUV like the full-size Range Rover.

Originally, the Land Rover Discovery was a less agricultural version of the Defender, featuring better bodywork and a more comfortable interior. Over the years, the Discovery evolved into something more akin to the Range Rover but retained its off-road prowess.

The Discovery Sport was launched in 2014, as a replacement for the outgoing Freelander. It was incredibly successful, appealing to those looking for a luxurious yet compact SUV. It stands a good bit smaller than both the Discovery and the Range Rover. 

Both cars are on the larger side, being compact SUVs, check out the table below to compare the two:

From the stats above, we can see the Evoque is smaller in every dimension, with its height being considerably shorter than the discovery. This gives it a much sleeker look, with notably shorter windows in the front and back. 

Interestingly the boot space is very similar on both, despite the Evoque being 240mm shorter. There is also less than a tennis ball's width between them, meaning any parking spot or tight road you navigate will be as difficult in either car.

Both the Evoque and the Discovery Sport have hybrid options, you can have either a petrol or diesel plug-in hybrid. Both engines are derived from BMW units, so should be pretty reliable. 

Both cars can be optioned with many of the same engines, with multiple petrol and diesels for both. Starting with the smallest, a 1.5 petrol MHEV powertrain is available giving good economy but mediocre performance, especially in the larger Discovery. The next size up being the 2.0.

If you do longer journeys or tow a trailer, a better option might be the one of the various diesels in the range. The most popular being the 2.0 MHEV, producing 201bhp and a substantial 429Nm of torque. 

As the engines are the same across the models, it's really down to how you plan to use the car, as to which one will suit you best.

Whilst the Range Rover Evoque and Discovery Sport are from different sub-brands, the design philosophy is evidently shared. The shape of the headlights, front wings and grille are very similar.

Both cars hit the nail on the head for the luxury SUV segment, with stylish and sleek look accents to the overall look. With its higher roofline, the Discovery Sport does show its roots to a utility vehicle a little more, but not so much to mistake it for anything other than a luxury SUV.

Inside, both cars share the same steering wheel and infotainment screen. The dashboard and centre console are both evidently from the same designer too. One thing to differentiate is the Evoques' slightly more contoured seats and centre console. 

If buying on the second-hand or nearly new market, you're much more likely to find an Evoque with a coloured interior than the discovery, the latter being almost exclusively supplied in matt black finish.

If you look at the reliability scores for both cars, there isn’t much between them, both score around the same level, with the Discovery faring slightly better across most categories.

In terms of warranty, both cars come with a 3-year, unlimited mileage warranty, so it would probably serve you well to buy new or nearly new, rather than off-lease unless you have a decent aftermarket warranty. 

Repair costs for Range Rover products are some of the highest of any brand, so bear this in mind when making your decision.

As you’d expect, both cars received a 5-star NCAP rating at the time of launch. The Evoque’s adult occupancy rating is the only standout rating of the below stats, putting it a good way ahead of the Discovery Sport.

In terms of airbags, collision avoidance and other safety features, there’s nothing between them.

The Discovery Sport starts at around £43,445 if you configure one direct from Range Rover, you may be able to get a discount on a forecourt car though, especially if you're quick, considering the new reg will be arriving in April.

The Evoque is around the same price, at £43,700, again you could possibly pick up a deal from a main dealer if you’re quick. This puts the cars directly in competition with one another, meaning the decision between the two is based primarily on their looks, practicality and taste.

Both models offer multiple levels of equipment specification, with everything from adaptive cruise control and sunroofs to towing packs and sporty seats on offer. 

If you want an SUV that focuses on style and sleekness, the Evoque is the perfect choice, being the baby in the Range Rover lineup. If off-road capability and load-carrying capacity are the be-all and end-all, the Discovery Sport will offer more in both departments.

Once in the cabin, there’s not much you’ll do to notice the difference, with fit and trim being relatively similar. Ultimately both will offer an incredibly luxurious alternative to the more bare-bones compact SUVs on the market.

 has been writing about cars for over seven years and writing for Bumper for over two, blending his passion for automobiles with a talent for storytelling.

Joseph has written about engineering and cars for Autozilla, Komaspec, and several engineering manufacturers. When he's not writing or tinkering with one of his cars, Joseph dreams of owning an Alfa Romeo 33 Stradale.

Range Rover Evoque Vs Land Rover Discovery Sport

The Mercedes A-Class is a popular choice for drivers looking for a compact luxury car offering a sleek design, premium features, and a comfortable ride. But when it comes to reliability, does it live up to the brand’s reputation? 

In this guide, we’ll break down the most common Mercedes A-Class problems, and what to watch out for, whether you’re already a proud owner or are thinking of getting one for yourself. 

While the A-Class delivers on style and performance, it’s not without its issues when it comes to reliability. Some previous owners have reported anything from loss of power to automatic gearbox faults. 

Whether you're considering buying one or already own an A-Class, it’s worth knowing the most common faults and what to look out for.

A-Class owners often complain about a loss of power, which can be caused by several issues. Common culprits include fuel injector problems and engine oil leaks.

If your A-Class is losing power or coughing out a lot of smoke, a faulty fuel injector could be the cause. If this is the case, a fuel injector repair will not only improve performance but also prevent bigger issues like clogged injectors and engine damage.

Engine oil leaks are another known problem in the A-Class. If you leave them too long, low oil levels can damage your engine over time. Think your A-Class might be leaking? Keep an eye out for oil patches under the car, a burning smell, or warning lights on your dashboard – catching one early could save you from expensive 

The A-Class is often fitted with a dual-clutch automatic gearbox, which is designed for smoother, more responsive shifts – but owners have noticed some common problems, especially with early models.

The automatic gearbox in some A-Class models can feel slow to respond, especially at low speeds, which can make stop-start traffic a pain. If gear changes feel jerky or delayed, it could be a sign of a bigger problem with the dual-clutch automatic gearbox.

Key internal parts inside the automatic transmission can wear out quicker than expected, which can lead to some very expensive repairs. 

Transmission issues like slipping gears often start small but tend to get worse quickly. Catch them early to save yourself from expensive 

Some electrical issues in the gearbox can be fixed with a software update, but more serious faults may need a full gearbox replacement. 

 can really set you back, so it's worth checking for any warning signs before they spiral – whining or grinding noises when changing gears and a burning smell are common red flags. 

for your Mercedes A-Class? There’s a smarter way. With Bumper, you can split your repair bill into interest-free monthly payments – no credit checks, no hidden fees.

Like most modern cars, the A-Class is packed with electronic systems. While this adds plenty of high-tech features, it also means a higher chance of electrical issues cropping up.

Some Mercedes A-Class models struggle to start due to starter motor faults. If you turn the key (or push the button) and nothing happens, a worn starter motor could be the culprit. Ignore it for too long, and you could end up stranded with an expensive repair on your hands.

A-Class owners have reported all sorts of electrical issues with the infotainment system – frozen touchscreens, unresponsive controls, and dodgy connectivity. In some cases, a quick software update sorts it out, but bigger problems might mean replacing the system entirely, which isn’t cheap.

Some A-Class models have issues with the passenger airbag sensor, which can trigger warning lights. In the worst-case scenario, it could even stop the airbag from working in a crash. If the airbag light comes on, it’s best to get it checked sooner rather than later.

The Mercedes A-Class is absolutely worth owning if you want a car that combines luxury with strong performance. But, like any car, it comes with its share of common faults that can lead to needing 

If your A-Class needs repairs, don’t let the cost hold you back. With our 

, you can get it sorted today and spread the cost over 6 interest-free monthly payments. Approval is quick and easy, so you’ll never be left waiting, and with over 5,000 trusted service partners across the UK, there’s always a garage nearby. 

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Voluntary termination (or VT for short) helps you get out of a car finance contract if you can’t keep up with the payments. 

Today, we're diving into how voluntary termination of car finance works, why you might consider it, and the financial impacts involved, so you can make an informed decision that’s best for you.

What is voluntary termination of car finance?

Voluntary termination (VT) is a term used to describe ending your car finance agreement before the official contract end date. 

, this option has been available for all UK drivers, provided they meet the relevant criteria. 

If you choose Voluntary Termination (VT), your finance contract ends, and you must return the vehicle—meaning you can’t keep the car. This option protects drivers facing financial changes, providing a safeguard in challenging circumstances.

Voluntary termination vs voluntary surrender

Voluntary termination and voluntary surrender may sound similar, but they’re very different concepts. Here’s a quick breakdown:

Knowing the difference between the two can help you avoid any confusion when filing your application, and will save you future charges!

What are your rights under the Consumer Credit Act?

Section 99 of the Consumer Credit Act 1974.

This grants consumers the right to terminate regulated hire-purchase or conditional sale agreements before the final payment is due. 

To exercise this right, you must have paid at least 50% of the total amount payable under the agreement. This total includes the vehicle cost, interest, and any additional fees outlined in the contract. 

If 50% has not yet been paid, the consumer can make an additional payment to reach this threshold and proceed with the termination. 

You must fulfil these terms and conditions to be eligible for VT. 

Reasons to file for voluntary termination

There are a few common reasons for filing for voluntary termination, such as:

The reasons mainly surround finances and being able to afford the car. It’s not an option for those who just fancy a new car and want to get out of their contract.

How voluntary termination car finance works

Voluntary termination is an option for new and used cars financed through PCP or HP agreements. 

The general steps to apply and start VT include:

You can ensure a smoother transition by documenting your vehicle’s condition, maintaining clear communication, and by keeping a record of all phone calls, emails or letters.

If you’re ever unsure, contact the finance provider for more information.

In a PCP agreement, the 50% threshold includes interest, fees, and the 

, not just monthly payments. Even halfway through your term, you may not have reached this amount. 

If you haven't, you can pay the difference to qualify for voluntary termination, but any payments beyond 50% won't be refunded.

HP (Hire Purchase) voluntary terminations are much simpler than PCP. 

HP contracts don’t have any lump-sum balloon payments. Rather, your repayments are spread evenly across your term.

When you reach the halfway paying point, you automatically qualify for the 50% payment requirement. You can even pay the difference to get to the 50% mark if you’re slightly short of this amount.

How long does voluntary termination take?

Once you apply, voluntary termination is a quick process. 

However, finance companies aren’t usually keen on this process, and may lengthen the application time if you’re not clear about your circumstances.

Want to speed up the process? Ensure you clearly understand what you want, know the difference between voluntary termination and surrender, and meet the necessary requirements.

Financial drawbacks of voluntary termination

Exercising voluntary termination can have several financial consequences you may want to consider. These include:

Advice

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