Petrol engine - use super unleaded?

un1eash

Pretty much all petrol cars sold in the uk are setup for 95 ron, fifth gear did some tests a few years back and it showed petrol turbos do respond better to higher octane fuels.

Modern cars are so advanced they avoid knocking with lower octane fuels so can't see much if any damaged being caused using them.

noiseboy72

Is the car tuned for higher octane fuels? My Z4 2.5si Sport is and does benefit, with slightly smoother running, particularly at higher revs. The manual says it will run on octanes between 95 & 99, so it lives on supermarket fuels for most of the time and has a tank of good fuel about one in 6 fills. For a 12 year old car, it still hits its published 0-60 time, so I'm quite happy with the performance

My wife has a Ford Ecosport with the little 1L 125hp motor. There's no discernible difference between fuel types in her car, so that lives on Asda fuel.

mjn

Alternate between regular Shell and V-Power Diesel.

MrMister111

So a nice full tank of super will do it good? I'm not mechanical but how will this help if do it every 6 tanks say, over just not using it?

noiseboy72

If it's tuned to run on it, then yes, you will see an increase in power while it's in the tank. Otherwise, just good quality fuel now and again to give it a rest from the Supermarket fuels.

MrMister111

How do I know if it's tuned though to it? Manufacturer manual states "recommended 95, possible 98"

Got advice though thanks, is it ok to mix as in if pass a Shell and still 1/2 tank left to fill up with super as nearest Shell I'd have to make a purpose trip, whereas Asda petrol pass night on every day

noiseboy72

Try it and see if it feels smoother and more powerful. in my Z4 it does, in the wife's Ecosport, no difference at all.

MrMister111

Interesting, I probably won't notice tbh, it gets me where I want to go ha ha...

But if better for engine I'm all for that, think will try it for a while exclusively with super, then Asda, then every few tanks treat it then as others mention!

enigma1701

I just use supermarket standard fuel, I'm sure I filled my car up once with super and I noticed no difference at all in it's running or mpg.

It's built to use 95 so why pay more. It's 6 years old now and never missed a beat so I find it dubious when reports say it's better for the car.

MrMister111

That's my question, I really don't think I'll notice, but was just wondering really, mine states use 95 as well.

Really wonder what mechanics or if a proper survey has ever been done to say either way.

Always read to keep away from supermarket but never she if true or just urban legend!

Surely it'll be like a lot of manufacturing, whereby come off same line/process just stick different badge on at end?