Guide to E10 Petrol: classic cars and performance cars

The new standard for petrol has now changed to E10 fuel in a bid to help fight emissions. It’s now the main type of petrol you’ll get at petrol stations around Great Britain as of summer 2021. Most drivers need not worry, as the government have stated that it’s fully compatible with 95% of cars.

But what if you’re driving a classic car or high-performance model? We’ve put this guide together on E10 fuel for specialist and performance cars to answer any questions and demystify this new change.

This has been in the works for a while now, with owners of classic cars and older vehicles worried about the change. The first thing you need to do is check your car on the government’s online compatibility checker, with the information going back as far as the 1990s.

What is E10 petrol?

E10 fuel is petrol that’s made with up to 10% renewable ethanol. This change is to reduce carbon dioxide (CO2) emissions, rather than helping with air quality. By using petrol with a higher amount of renewable ethanol, your car burns less petrol, in turn producing less emissions.

Putting E10 petrol in classic cars is not recommended. Why? There are two main reasons. 

• First: ethanol is corrosive. So with there being a higher percentage of ethanol in E10, there’s more risk of corrosion on any metal, plastic and rubber in your classic car’s fuel system. This can result in many different issues, from fully broken fuel lines to carburettor issues.

• Second: ethanol is hygroscopic. This means it absorbs water. This poses a much bigger issue when it comes to E10 fuel with classic cars, as the longer you leave your car idle in the garage, the more issues this added moisture may cause.

This means that continued use of E10 petrol in your classic car may cause some serious issues, for driving and safety. Especially if you leave your car for extended periods, like most classic car drivers do.

So, what can old classic car owners do about the E10 fuel change?

Classic car owners have two options when it comes to the recent E10 fuel change.

1. Keep buying E5 petrol

Don’t worry, as you can still get E5 ‘super’ grade 97+ octane at most filling stations. You just have to know where you need to go. Once you’ve found a petrol station that serves E5, you’re set. This is probably the easiest method, but might be more difficult for anyone in rural or hard-to-reach locations. E5 petrol is likely to go up in price, too.

2. Upgrade your classic car’s fuel system to handle E10 petrol

Or you can future-proof your classic car by upgrading your fuel system so it can handle E10 fuel with no problem. This is the more costly and time-consuming method, but probably the most effective. If you upgrade your fuel system to handle the new petrol fuel type, you won’t have to worry about finding E5 petrol anymore.

Contact us to learn more about manufacturer-approved servicing at Dick Lovett.

Be careful when doing this though, as you need to make sure that all parts you replace are compatible with E10 petrol.

It’s best practice for classic car owners to keep on top of fuel lines anyway, as any damage to the hose can be catastrophic. Once you’ve got this sorted, you’ll no longer have to worry about the change to E10.

What about modern classic cars and E10 petrol?

If you have a modern classic car built from the late 90s onwards, you’re more than likely covered. Most modern cars can handle E10 petrol, but it’s worth checking it on the government’s site as there are a few exceptions.

For example: if you own a BMW M3 E46 or upwards, you’re completely fine. All BMW cars from the M range are E10 compatible.

What do I do if I fill my classic car with E10 petrol?

It’s not the end of the world if you accidentally fill your classic car with E10 petrol. It will still run perfectly fine and you most likely won’t encounter any issues, as long as you don’t let the fuel sit in the tank for too long.

Your best bet is to empty the tank as much as you can by driving around, and then refill with the correct E5 97+ octane petrol next time.

So if you fill your classic car’s tank with E10, you don’t need to drain it, unlike when you put petrol into a diesel engine. It’s only prolonged use of E10 that would create any issue.

E10 fuel in performance cars: am I affected?

The E10 change shouldn’t affect modern performance cars either. But it’s still worth double-checking. New carsa tend to be fine, with older vehicles being most affected.

If you have any questions regarding E10 petrol for classic cars, or anything else regarding the fuel change, get in touch. If you’re after your next vehicle, we can run through which of our used cars are E10 compatible. Or you can book your specialist or performance car in for a service.

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