Years ago when I first owned a car the rage used to be to add Redex to the tank to help it run more smoothly. Nowadays I just use normal 95 fuel from Tesco near by. But as I’m about to go on a long motorway journey is it worth using Momentum or Redex?
It’s a SEAT Leon 1.5.

No.

If you’ve got an actual problem, like gummed up carbs from being left standing with old fuel for a long time, there are some like Seafoam which can help clean them up. If you don’t have an actual problem, it’s a waste of money. And if you do have a problem, there are plenty of additives that are probably a waste of money, too.

Spend the £3.50 on a coffee and a Lion Bar Duo.

Nope, it’s a 1.5 run of the mill designed for 95RON fuel engine

From what I read they do more harm than good.

Apparently worth using posh fuel every so often

Ok dokey. Thanks, I’ll keep me money in my pocket.

Apparently worth using posh fuel every so often

I use an app that tells me fuel prices locally – and the local Shell garage keeps being the same price as Tesco or Sainsbury’s. My 1.4tsi gets another couple of mpg on the standard Shell, let alone posher Shell. Measured with a calculator over a few tanks as I didn’t believe the car – and of course every week of driving is different.

Redex or similar does help to keep it clean every so often. Like, every year or something.

There are some good additive brands and some terrible ones can’t remember the good ones form the bad ones. Some use old recipes form decades ago which either makes no difference or is actually bad for your engine and some use more modern recipes which work better and are good for your engine.

But in general its better just to use posh fuel, Shell V Power or BP Ultimate or whatever Esso have etc… Its pre-mixed in the right quality and made up of update to date modern recipes.

A common mistake with additives is people think a little is good for the engine so a lot must be even better right ? So people dont mix it with the recommended dilution and make it too concentrated which can have other side effects.

Mostly likely a standard engine won’t make more power and any extra efficiency gained is offset by the extra cost compared to standard fuel. So not worth it from that point of view. But they do genuinely help reduce carbon build up in your engine and other nasties and help keep it running smoother.

A full tank every now and then should be good enough to keep the inside of the engine clean, I don’t think you need to do it all the time.

I’ve been using fuel from Sainsbury’s for ages, because it’s been cheaper than anything else around for months, and it’s still 1 or 2p cheaper now. The car runs really well on it, it had an oil and filter change about six months ago, and it’s run better after that than using any super whizzy fuel. The motor is a little 1.0 EcoBoost turbo, the planned remap will make the biggest difference. I might top up with V Power or Ultimate once in a while, but the last time I did by accident, I couldn’t really tell any difference, tbh.