5 tips for looking after your classic car from Redex

Looking after your classic car can sometimes feel like a full time job. There is always something that needs doing from keeping the engine and gear box oil topped up, to keeping the dreaded tin worm at bay. But there is one area that can sometimes be overlooked. And that is looking after the cars fuel system. Because there is nothing worse that carbs or injectors getting gummed up with stale fuel or dirty deposits. But there are ways to prevent this from happening. So as part of Take to the Road’s recent trial with Redex, we had a chat with Redex and got some tips on looking after your classic car.

1. Classic car owners like to keep their motors running smoothly. Are there any Redex products that would suit classic car owners?

We work on problem solutions when we come to design our products. When it comes to classic cars in particular, some were designed to run on leaded fuel. Leaded fuel was designed to maintain and lubricate valve seats, to ensure you get a good seal and have good compression. The lead additive turned out to be a bad idea so it was removed.

One of the best ways of looking after your classic car is to use a lead additive especially if it was designed to run on leaded fuel

If you use unleaded fuel in a car that was designed for leaded fuel, then you get valve seat recession and hardening of the valve seats. That would then continue until you needed head work, which by that stage is irreversible. So we have our Redex Lead Replacement Multidose product that helps prevent damage to the engine.

It’s important to keep your carbs clean as rebuilds can be time consuming and expensive

There is also our Redex Petrol System Cleaner which we recommend. This helps keep the fuel system clean by removing deposits that will have built up over the life of the car.

2. How does the Lead Replacement Multidose work?

Our Redex Lead Replacement Multidose replicates the function that lead would have added to the fuel. It maintains the valve seats and lubricates and maintains their softness. It treats more than one tank as well. If your car is supposed to run on leaded fuel you might not notice any symptoms until the harm is already done. So if you are in doubt it is a good idea to get your engine checked.

If in doubt check to see if your engine is supposed to run on leaded fuel

3. How often should classic car owners use petrol additives?

You should use petrol system additives and cleaners regularly to help keep the fuel system clean. This also helps when your classic car is in storage. The recommendation is to run your petrol tank down low before putting your classic car away for winter, or if it’s going to be off the road for a while. Oxidization of fuel in the tank is a problem when a car isn’t used. It basically goes stale over a prolonged period of time. So it is not a good idea to leave a lot of fuel in the tank.

As Take to the Road recently learned with its Vauxhall Viceroy, a gummed up carb is a massive pain! An example where looking after your classic car can be a huge headache!

Stale fuel can gum up your carbs, make it run rough and may lead to a carb rebuild. So using something like our Holts EGR Carb Cleaner would be a good idea when you are bringing your classic out of storage. And when you take your classic out for the first time, give it a tank of fresh fuel and add some of our fuel system cleaner. Then take it for a drive to get the cleaner working through the fuel system.

4. Should you use Redex before taking your car for an MOT?

We recommend regular use rather than annual use. But if you use it on an inconsistent basis it is a good idea to double the dose. It will help remove the deposits that can gather in the fuel system more quickly due to the concentrated mix of the product. So in the fortnight or month in the lead up to the MOT, put a double dose of Redex Petrol System Cleaner into the tank.

The advanced fuel system cleaner is recommended if you’ve never used a fuel system cleaner in your car before

Or you could use our super concentrated Petrol Advanced Fuel System Cleaner product, which gives a more intensive clean. Then take your car out for a drive to warm up the engine. This will activate the additives and help remove the deposits. Which will help reduce emissions and reduce the risk of failing an MOT on poor emissions. You can then follow up with our One Shot Boot pack which can use every time you fill up.

Classics like the Citroen DS23 used advanced electronic fuel injection
So keeping those injectors clean and in tip top condition is very important

Also worth mentioning are classic cars with fuel injection that now fit into the modern classic category. Some will have a more early iteration of fuel injection. So it is really worth keeping those clean and maintained as rebuilding injectors and a clogged up fuel injection system is expensive.



A build up of deposits on injectors ultimately affects the cars performance, fuel economy and reduces the longevity of the injectors themselves. It’s not something you can see happening as it is going on inside the engine, but using Redex will keep the injectors clean. So it is something to bear in mind.

5. Is there any risk to using petrol additives in older cars? Is there anything owners need to be aware of?

The increased used of ethanol in modern fuel is a concern for older cars. All the formulations we produce go through what we call a no harm test. Our products are tested on lots of different substrates, to ensure we are not causing any swelling to gaskets for example. There’s also lots of engine tests where we overdose with our products up to six or eight times. And we monitor the affects that level of dosage has on the system.

Every time you fill up think about using an additive to keep your classic running smoothly

The clean up process is actually pretty quick so no matter how you use it, no harm will come to your vehicle. As classics become rarer and more expensive it is important for our products not to cause any problems.

The key is to use them as part of your vehicles regular maintenance regime. That way your fuel system will stay clean, you’ll get more mpg and your classic car will drive better.

Thanks to Redex for their 5 tips for looking after your classic car

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