Whilst it may seem fairly innocuous, the fuel cap on your car serves a few very important roles. Even though they are a simple device they can still become worn or work less effectively over time, and in some cases stop functioning altogether. We’ll explain their main uses and what to do if your fuel cap is loose and what problems it can cause. 

The main purpose of a fuel filler cap is to prevent the fuel from spilling as well as evaporating from the tank. 

Petrol, if left open to the air, will evaporate all its volatile chemicals within hours, causing the fuel to become stale and much less energy dense. The fuel filler cap prevents the liquid from evaporating and therefore retains the fuel's energy. 

If your fuel cap is broken or worn out, and the rubber seal is not making good contact with the filler neck, 

your fuel will evaporate from the tank much faster than normal.

The more obvious consequence is that the 

You may notice that if you don’t drive many miles, and your fuel cap is loose, the engine runs rough after a month or so, or fails to start at all. 

This would be due to the volatile compounds evaporating and the petrol becoming stale. 

If you notice your fuel cap is loose, the only real way to fix it is to buy another one. The mechanism that locks the fuel cap in place, and that seals the fuel from spilling, is all built into the cap itself, so there should be no issue with the filler neck or tank. 

The best place to source a filler cap would be the main dealer parts department, they will be able to supply an exact replacement of the original, ensuring there are no issues with sealing for years to come. 

It’s strongly recommended that you don't drive if your car is missing its fuel filler cap, 

not only would your fuel evaporate, but spills onto the road can be dangerous for multiple reasons. 

Other than the obvious flammable dangers of petrol spilling from your car, fuel on the road can be very dangerous for road users such as motorcyclists or cyclists, as it can make the surface slick as ice. 

If you're in a position where you’ve lost your fuel filler cap, and cannot get home without driving your car, you could try a couple of short-term solutions. 

Buy a universal filler cap in a garage or supermarket - lots of petrol station shops sell ‘universal’ fuel filler caps. Borrow one from another car - ask your friends and family if they have a similar car or make. 

Don’t use a rag or item of clothing (socks are quite common!) as a makeshift cap. 

The porous material can allow the vapour to still pass through, and petrol can still seep out when the fuel sloshes around.

Most of us will have some supermarket bags stowed away in the boot, in a pinch these can be used as a cap, but make sure they don't fall into the tank, fall out or allow dirt into the system. 

Most fuel filler caps are inexpensive, between £15 - £30.

 If however, your fuel cap has a lock built into it, you may find it can cost upwards of £100 to get one that will work with your car key. 

In the event you lose your locking fuel filler cap, an alternative is to buy a universal locking cap, or one from a different car with the key supplied. 

This may mean you need to keep the fuel cap key in your car separately (don't lose it!) but will be cheaper than getting one made to suit your key.

Most manufacturers have their own variation of filler caps, the main differences being the way the devices lock into the filler neck, with some using a half turn, some by the key and so on. 

However as many manufacturers are sharing parts nowadays, you may find some brands fit others, common ones include Volkswagen, Seat and Audi - BMW and Mini - Jaguar, Land Rover and Range Rovers - and more! 

You can buy universal fuel caps, usually, each one will be advertised at a specific set of car makes so make sure you’re getting the right one! 

Modern rubber seals and tough plastics mean most drivers will never need to replace a fuel cap in their car’s lifetime. 

Exceptions may be if the cap is damaged by yourself or a previous owner or if you notice fuel leaking from the cap after filing. 

If you’ve noticed petrol around the filler cap of your car after filling, it might be leaking from the fuel cap or from the tank itself: 

Noticing petrol on the floor underneath your car can be indicative of a serious issue, as a leaking tank can be extremely dangerous. 

Firstly, check the location of the leak, if it’s to the rear, on the same side as the petrol cap, there’s a good chance it's from the petrol tank itself. 

Modern cars often use plastic fuel tanks, and there are a few failure points, one being the connection between the filler neck, the tube that runs from the filler cap to the tank, and another being the tank itself. Sometimes the metal straps that hold it in place can wear through the plastic. 

Issues with the fuel filler neck can sometimes be rectified by removing and refitting the connection with new fasteners. However, issues with the main fuel tank will most likely require a new tank assembly. 

If you notice fuel running down the side of your car, particularly shortly after filling up, it may be a sign your fuel cap is not sealing properly. 

Open the fuel filler door and inspect the area for signs of fuel leaking. 

It may be hard to detect leaking fuel in anything but very cold weather, as petrol evaporates readily above freezing temperatures. The best solution may be to buy a new fuel cap and so if that resolves the problem. 

As car issues can quickly get expensive, try Bumper for zero-interest car repair financing, and choose from hundreds of approved partners across the country. Find your nearest approved partner. 

 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 Happens if your Fuel Cap is Loose?

Was passiert, wenn Ihr Tankdeckel locker ist?

Whilst very small, and hidden away out of sight, the fuel filter is a component present in every petrol or diesel-engined car, which contributes a significant amount to the smooth running and reliability of modern vehicles. 

This article will go into the ins and outs of fuel filters, including how they work, when to change them, how much a replacement fuel filter costs and more. 

It may seem self-explanatory, but it's important to understand the role of fuel filtration in modern cars, which is more vital than ever. 

Once refined from crude oil, the petrol or diesel may well travel thousands of miles to get to your tank. During this time it will travel through ageing pipes, tanks and valves. 

All this results in an end product that is often quite far from perfect, with sediment, dirt and other impurities being present. Due to the traditional usage and production diesel tends to contain more impurities than petrol. 

How much do fuel filters cost to replace?

The average cost to replace a fuel filter is £105, with prices ranging from £70 on older/simpler cars, and up to £150 on premium/luxury brands. 

Split the cost of car repairs into monthly payments at 1000s of garages and dealerships. 

Often fitted in line with the fuel line, between the fuel tank and the fuel system in the engine bay, all fuel flow is routed through the filter, and subsequently through the filter elements. Any pieces of debris or dirt are captured in the filter elements, preventing them from entering the fuel system or engine. 

Almost all fuel filters fall into one of two categories; inline and cartridge. 

 is a plastic or metal unit with tube connectors in each end, a flexible fuel hose is connected to these, with the fuel line passing through the unit from one end to another. 

 use a plastic housing with a removable ‘bowl’, inside the bowl sits the filter element. To replace the filter element, the bowl is unscrewed, the filter replaced and the bowl re-attached. 

There is no inherent benefit to either type, and the type of replacement filter you need to buy will depend entirely on the manufacturer’s design - it’s important to note the two types are not interchangeable - most garages or auto parts stores will be able to search up which part you need.

How often should you replace a fuel filter?

Fuel filters should be replaced every 30,000 miles or two years of use

, but check your car’s manual for more precise information. 

As the fuel filter is not an overly expensive service item, it’s not worth neglecting to change it as part of your bi-yearly service schedule. 

Major services will typically include a fuel filter as standard.

 While the car is on a lift, it would be a relatively simple job for a mechanic to replace it. 

For more information on what services include, check out our 

Over time the elements become fully saturated with debris, and will both allow some contaminants to pass through, as well as restricting fuel flow to the engine, causing starting and running issues. 

Some cars have larger filters that can last longer between changes, but even these will need replacing after they’ve been functioning as intended for a long period of time. 

What happens if you don't change your fuel filter?

Naturally, a good uninhibited supply of fuel is vital to an internal combustion engine, but there are various problems that can indicate you may benefit from replacing your fuel filter: 

Will a new fuel filter improve performance?

Yes, if your fuel filter is very old, there is a good chance a replacement one will improve engine performance. In modern cars, engine fueling is adjusted to take account for the quality and pressure of the fuel supply. A new fuel filter will allow a better fuel flow to the engine, meaning improved performance may be noticed. 

Changing a fuel filter is a relatively simple process. As many inline filters are near the fuel tank, you’ll likely need to get underneath the car - which requires extreme caution and attention. 

If you have the space, tools and expertise to safely jack up and support your vehicle, the only other tools needed are basic hand tools including screwdrivers and pliers to pull off the fuel lines. 

If you are at all unsure about jacking and supporting your vehicle, and your fuel filter is underneath the car, do not attempt to change it yourself, we’d suggest including it as part of your service via one of our 

Split the cost with Bumper at 1000s of approved partners. 

Fuel Filters: Everything You Need To Know 

With many people changing their cars every 2-3 years, getting the best deal on a car can save some serious cash. 

In this article, we’ll discuss the cheapest way to buy a new car and the best places to look. So, what are you waiting for? Start reading now to secure your next deal!

Cheapest way to buy a car - the top 9 strategies 

From cash transactions to buying at the right time, these are the cheapest ways to get a car in the UK. 

If you can afford to, buying a car with cash is always the most cost-effective option. It can avoid the downsides of the above finance options and work out considerably cheaper, but there are still points to consider. 

The finance vs cash decision is something that can take quite a bit of deliberation. Whilst financing can allow you to purchase a more expensive car without needing to outlay a large chunk of cash, it can end up costing significantly more in interest. 

Cars grow older and out of fashion and their prices drop significantly. This might not be the best option if you’re looking for a new, shiny car. However, it's a great way to get a good deal if you’re not fussed about brand names or car age.

Financing a car isn’t always the cheapest option, but it can be if you secure a favourable deal. 

To decide, first familiarise yourself with the different types of finance available including 

Hire Purchase (HP), Personal Contract Purchase (PCP)

, Bank Loans or Personal Contract Hire (PCH). 

Once you’re in the loop, you can start shopping for low-cost car finance. Look for deals with a low overall total cost rather than low monthly payment. To find a low total cost, you need to assess the length of the loan, the amount borrowed, and the interest.

Your dream car might not match your budget, so don’t be fixated on a certain brand or model.

Instead, assess your daily needs, look for cars that tick these practical boxes and explore brands you wouldn’t usually consider. You might be surprised at the prices you find! An open mind is key when looking for cheap cars.

Setting a budget is paramount when car shopping. But don’t be tempted to go slightly above or discard the budget altogether! 

Of course, there are some situations where you’ll need a bit of wiggle room. However, remind yourself why the budget is there. It’s to protect your finances and guide you to a car that’s right for you.

The used car market is one of the best ways to secure an affordable car. Prices for used cars are much lower than their newer counterparts, and they’re often just as high-quality. This is because car prices depreciate over time.

Used cars can be found online and at specialised dealerships. Look for certified pre-owned cars, which come with warranties and can offer extra peace of mind.

Sometimes, buying directly from a private seller can be much cheaper than buying from a dealership. However, you must check the car’s history and get it inspected by a garage before you confirm the sale. This way, you can be sure the car is safe and up to current standards.

Online auto marketplaces are a great way to compare the best deals in one place and make quick comparisons. Autotrader, Kazoo, and eBay Motors are popular websites for UK buyers.

Did you know that dealers sometimes offer discounts and sales at the end of each month or quarter? That’s right. Since they need to meet targets, they often decrease the prices at the last minute.

Similarly, brands sometimes offer year-end sales, a strategy where you can buy last year’s model at a lower price. This happens just before the new models go on sale and it’s a technique dealers use to clear their inventory, offering you significant savings.

Since the internet, there are more ways to buy a car than ever. If you’re patient, willing to take a risk and have the knowledge (or a knowledgeable friend) on car faults, Facebook Marketplace and eBay can yield the best bargains. 

Here are some FAQs about the best places to buy cheap cars:

Is it best to buy a second-hand car privately or from a dealer? 

Generally, buying privately can get you more for your money, but with a private sale (from a non-business), you get no warranty or refunds. Sold as seen means you must find out if anything is wrong with the car before buying. 

Car dealers exist for all price points. The likes of 

 offer a wide range of nearly new cars, all with finance available. 

Car purchases from a business are covered under a specific section of the Consumer Rights Act, meaning if something goes wrong within a specific time period, you can get the garage to fix, replace or refund the car. 

Buying from a dealer typically costs 10-25% more than from private sellers. 

online auction place, eBay has been the place for bargain hunters to pick up all kinds of items since its creation. Buying cars on eBay is certainly not out of the ordinary, with a specific site set up to do so. 

The benefits of buying through eBay, are found if you are patient. Whilst they are less common than they used to be, many people still run auctions on cars starting at very low prices. 

As well as a well-respected auto magazine, Autotrader has a long history of including car adverts, nowadays their website is still one of the most visited by those searching for vehicles to buy.

Adverts tend to be better listed than those on the marketplaces, this is because the adverts cost upwards of £20 list, meaning whether private or business, the seller takes more care over the description and photos. 

Since Facebook launched its marketplace a few years ago it’s become one of the most populated places to buy and sell online. There are some great bargains to be found, as there is so much competition on the platform.

When using these kinds of marketplaces - Gumtree included - it’s advisable to exercise caution as there are often various scam listings, we advise to never send money without seeing the car, even a deposit, and make sure you take care when viewing cars. 

The cheapest way of buying a car - the takeaway

The most economical way to buy a car can change depending on your circumstances. However, the strategies and places on this list should give you plenty of avenues to explore. 

Bookmark this page for your convenience, ensuring you always have the cheapest way to get a new car at your fingertips!

Once you’ve bought your new car, repairs and maintenance are inevitable, with 

, we can help spread the cost into interest-free instalments. Find your nearest 

What is the cheapest way to finance a car?

PCP and HP are the best ways to buy a new car with finance, but which one is better will depend on the interest rate offered. The various finance deals exist to allow those with different circumstances to pick one that best suits their needs.

With HP, as the name suggests, you are paying monthly towards the cost of the car, after an initial deposit. Until all payments have been made, you do not own the car - hence 

 Purchase. When the last payment is made, the car is legally yours.

Unlike PCP, there is not a large payment to be made at the end, but there may be a small transfer of ownership fee.

What is PCP? (Personal Contract Purchase) 

Another common way of getting hold of a new car is PCP, a monthly payment is made (often with a deposit at the start). At the end of the contract period (usually 4-5 years) a 'balloon' payment is required to purchase the car.

Whilst the name suggests the car is purchased, this is not a requirement of the contract, as you can return the car at the end of the term, if you do not wish to or cannot afford to pay the balloon payment.

Personal contract hire is very similar to leasing, in that you can pay a small rental fee to begin the deal, and then a moderate monthly payment for the duration of the contract.

At the end, the car is returned to the financier, and there are no more fees to pay (apart from any damage or mileage outside the terms stipulated).

PCP can be a great option if you want to drive a brand-new car, but don’t want to own it, as the monthly fees are constant during the contract period.

Banks will lend money for large purchases such as cars at reasonably good interest rates, especially when compared to most finance deals like HP or PCP. 

Once the loan is acquired you buy the car outright as if you are paying with cash. This means no finance contract with the dealership/trader. If your credit score allows and you wish to own the car outright, this can be a good way to go. 

Many car loans are ‘secured’ against the car meaning the bank will seize the vehicle as a way to get their money back if you don’t pay. 

Downsides of using a bank loan to buy a car 

If you are buying a brand-new car, you should consider the fact that it’s likely to lose half its value in the first three years. If you are set on a brand new car, and you don’t want to consider leasing or PCP, try to avoid certain makes and models to reduce the hit on deprecation.

The best cars for depreciation are listed on the Money Saving Expert’s website 

, with MINI, Audi and Volkswagen taking the top places.

In some instances, the depreciation over the first three years may be more than the cost of leasing, so make sure to do your research.

What is the most cost-effective way to buy a car?

If you can afford to, the cheapest way to buy a car is with cash, 

as you won't pay any interest on the money you've borrowed. 

If you’d rather not get finance and cannot afford a new car, there are some great second-hand cars available for all budgets.

Most Cost Effective Ways To Buy A Car

Formas más rentables de comprar un coche

Die kostengünstigsten Wege, ein Auto zu kaufen

While using a car regularly causes wear and tear on the engine,

, and other components, leaving a car unused without starting it can cause problems in itself. 

That’s right. Leaving a car unused can result in damage. 

If you stop driving your car for an extended period, you should be aware of the best practices to keep it safe. In this guide, we’ll examine how long you can leave a car without starting it and how to start a car that’s been sitting idle for months. 

What happens to your car if you don't use it? 

Wondering what happens if you don’t drive your car for six months? You’re not the only one. Here’s what to expect after storing a vehicle. 

Leaving a car to sit can cause damage and require the replacement of certain parts, such as: 

Rubber perishes with time and exposure to sunlight, even when not used. This is accelerated by the 

 having low pressure from a slow puncture or not being inflated regularly. 

If the tyres lose all their pressure, the sidewalls can crack, and the tyres develop a ‘flat spot’ in a matter of weeks, rendering the tyre too damaged to be used. 

Hoses are used in various systems in modern cars, including 

. All rubber hoses deteriorate faster when not used, meaning leaks can develop in various places after a few months. 

 and engine mount bushes are made of rubber, these also deteriorate faster when sat in the same position for a long time. 

Various systems like the alarm, immobiliser and even some 

 functions still operate even when the car is not in use. This is known as a parasitic draw and is impossible to avoid completely. Without frequent use of the car, it can deplete the battery. 

How long can you leave a car without starting it? 

You should start your car’s engine at least once a week and let it run for half an hour.

It would be ideal to drive the car for a short journey, too, as this would help keep the battery charged. This is a must if you’re not driving your car every day. 

How to keep the battery healthy in an unused car - three key steps

There are a few things you can do to stop the battery from being damaged from lack of use, with the correct steps a battery can be kept unused for years. 

Current draws from the car's electrical system, and temperature changes both affect the battery's health. Removing the battery from the car and keeping it inside, in a reasonably stable environment keeps the battery from deteriorating. 

Make sure to charge the battery fully before removing it, either by taking the car on a long drive or charging it using a 

Most battery chargers have a trickle charge function. This keeps the battery topped up with a small amount of current constantly, preventing the battery fluids from crystallising and diminishing the battery's capacity. 

If you don't have a garage or the ability to get power to the vehicle where it's parked solar-powered trickle chargers can maintain a battery purely from solar power. 

 and temperatures can affect a car battery’s health. So, store the car in a cool and dry place like a garage. This protects the vehicle against temperature fluctuations and saves you money on damage. 

If you allow your car battery to become fully discharged for too long or too many times, it will no longer have the same capacity as before and may need replacing soon. 

When a car battery discharges, the liquids solidify into crystals inside the battery. When the battery is charged again, the crystals are dissolved, and the liquid enables the voltage potential to be restored, restoring the power in the cells. 

The problem comes when the battery is fully discharged too many times or for a long time. The crystals build up excessively and cannot be effectively liquidated, which severely limits the capacity of the battery. 

Different time periods can affect the car battery differently. Here’s a rundown on common concerns. 

What happens to a car if unused for 2 weeks?

Modern cars should be okay left unused for two weeks.

It’s not enough time for the tyres, other rubber components, 

Before parking, top up the tyre pressures and the battery charge—even just by taking the car on a 

. Check that no interior lights or other electrical components are left on. 

What happens to a car if unused for a month?

30 days of inactivity for a car could cause some issues, especially for older cars. 

The most likely issue is a dead battery. This can be mitigated by either disconnecting and removing the battery or using a trickle charger, as described previously. 

What happens to a car if unused for 6 months? 

The battery will almost certainly be flat and unable to recharge.

Six months is quite a long time to leave a car unused. It is also likely that one or more of the tyres will have deflated. If a tyre has deflated, it will most likely need to be replaced, as the sidewall will have been stressed excessively at one point, causing cracking. 

Any fuel left in the car’s tank will likely have deteriorated to the point where the car will not run properly using it. 

What happens to a car if unused for a year or more? 

Even more issues occur after a year, such as rubber perishing.

This may present itself in small leaks on 

, vacuum or air conditioning hoses, and creaking/knocking suspension. 

To fix a car that has been left for over a year, it would probably need new tyres, some new suspension bushes, a new battery and a substantial inspection from a mechanic. 

Starting a car that has been sitting for 6 months

If you need to start a car that’s been idle for six months or more, there are some extra checks you need to make for your safety. These include: 

An overall service is always good if a car has been in storage. 

How to store a car for a long time - The conclusion

Leaving your car for long periods isn’t advised, but sometimes, it has to happen. Ensure you store your car properly and run the engine when possible to keep it healthy. Finally, check if the car is healthy before driving it again. Double-checking is key here! 

Split the cost of repairs, parts, and services into monthly payments at no extra cost. Choose from 1000s of participating garages and dealerships. 

How Long Can You Leave A Car Without Starting It?

¿Cuánto Tiempo Puedes Dejar un Coche Sin Arrancarlo?

Wie lange kann man ein Auto stehen lassen, ohne es zu starten?

Everything seems to be getting more expensive, and motoring expenses are no different. 

With the estimated cost for 2023 being over £3,000, the average car running costs will soon make up an even larger portion of modern life's costs. Energy bills can be reduced by lowering your central heating temperature and food bills by eating out less, yet car running costs seem to be immovable. 

Luckily, there are some ways we can save money on cars. Today, we’ll explain how to reduce car running costs with easy and actionable tips. 

Do you know the average running costs for a car in the UK? The answers might surprise you. 

 shows that the average UK driver spends £2,500 a year on car costs. Let’s have a look at the breakdown below. 

Factors that affect the average running costs 

The average car costs above give you a good insight into what UK drivers are paying. But these figures aren’t set in stone. There are plenty of factors that can impact these numbers. 

For example, the age and make of your car can easily swing the numbers. Older cars may need more servicing, and some cars may have higher taxes. Likewise, some drivers will have higher insurance premiums than others. 

Joseph Law

Bumper Content Writer

What Happens if your Fuel Cap is Loose?

Fuel Filters: Everything You Need To Know

Most Cost Effective Ways To Buy A Car

How Long Can You Leave A Car Without Starting It?

The Average Car Running Costs & How To Budget Them

What to Do If Your Car Is Faulty On Finance

Car Engine Blown While On Finance

Price Guide For Repairing Dents In Doors