Petrol engine - use super unleaded?

car-man

My experience of using 95 or 97 (8) octane fuels is that if your manufacturer recommends premium fuel then you should use it.
I have genuine experience with engine faults on certain vehicles which are recommended to run on 95 standard fuel which have been solved purely by using premium fuel!

The Peugeot 16 valve petrol engines can be a real pain (207, 307 etc.) I've had all sorts of faults with these engines over the years...engine light on, misfiring, bad starting, etc. All sorts of solutions have been tried but nothing worked until premium fuel was fitted!

My experience with supermarket fuel is that it doesn't make the slightest difference.
My experience is mainly with diesel...I have maintained 2 fleets of vehicles from new to over 100,000 miles plus on 60 vans and cars, plus my own vehicles....Tesco fuel for what it's worth.
The vans were Nissan, Vauxhall, Renault. The cars were Renault and VW.
I've been running a Renault Twingo petrol for a few months since I retired on Tesco petrol without issue.

I never had a single engine fault in any vehicle that used supermarket fuel!!!!
Aside from the Peugeot 16 valve engines.

enigma1701

@MrMister111 @car-man

I have to agree fully with both of you. I do read honest John and I know he pushes super but that's mostly for diesel engines. I would imagine if your running about in a Audi R8 etc that the 99ron stuff would be the fuel of choice as it's designed for it but our humble daily run about I'm not convinced, it's all just opinions of people in the biz.

It would be interesting to see a real study on this for Joe public but for me with my 1.6 turbo I'm happy with supermarket stuff!

un1eash

An R8 will happily run on 95ron, it even says so in the user manual with a note that premium is recommended as performance will be reduced on 95.

Epicurus

That's an interesting observation, what aspect of the petroleum industry does your father work in?

rousetafarian

Down in Plymouth on the tankers, specific job title unknown, (as it’s my father in law, not my father)

edward

I think some of the Audi engines perform exceptionally on Shell V-Power.  I use it sometimes in my A4 diesel sometimes. No performance difference that I notice; might be slightly better MPG for a while but not much.

I’ve also got a 1971 Triumph TR6 that has a history of being breathed on; Shell V-power with a shot of Castrol Valvemaster Plus really makes a difference.  In truth, I’m not looking at MPG in that thing but performance on a fresh tank definitely feels better and it’s not subjective.

DOBLY

Over here in NZ three grades of petrol are available 91, 95 & 98.  Most cars use 91, some need 95 and a few need 98.  In certain parts of the country, especially in more remote areas, garages only have 91.
< this car is designed to run on 98, so I buy that for it, but I have checked with someone I know who was involved in the design and manufacture of the car - he say that the car will run on 91, but not to use a full tank of it, but to put enough in to get to a garage that sells 95 or 98.  Using a mixture of 91 and 95/98 will do no harm (as will a mix of 95 & 98), but this isn't recommended for anything but the short term.  I haven't needed to put anything but 98 in yet, but may have to when visiting friends who live in a more remote area. The tank holds 70 litres, so as long as I top up with the highest spec fuel where possible, there shouldn't be an issue.

AMc

I bought a Golf GTi (Mk5) a few years back - 2 litre, turbo 4 cylinder engine (TFSI)
Played with buying the premium stuff and standard supermarket fuel and couldn't really determine any difference in power, running or economy so I stuck with the cheaper stuff most of the time.

About a year ago I had a couple of misfires under hard acceleration and the engine warning light flashed on, a couple more weeks and it lit and stayed on though the car ran OK except when really booting it.
I took it to my friendly village mechanic who spoke to the TFSI expert on his back up service.  They suggested the first thing to do was reset the light and run a few tanks with Redex (or similar) injector cleaner.  I remember Redex from back when I did my own mechanics and it used to make a difference - though that was pouring it into the cylinders through the spark plug holes then running it off in massive clouds of evil white smoke

I've been adding redex or engine lube in the tank and the light hasn't returned and it hasn't misfired since.
Redex or Engine Lube is about £2-2.50 for two tanks.  I pay about 10p a litre premium for Super at my local garage which on a 50l fill is £5 a tank.

IIRC the 5th Gear thing about premium fuel which can be found on YouTube showed about  5bhp from a premium fuel.
I also found a thing on another motoring site that showed a 10yr old GTi got the best performance boost per £ from a few tanks with Redex - IIRC about  5bhp

I also put a few tanks through our 12yr old supercharged Mini Cooper and it now runs more evenly.

So I have a bottle in the boot.  If Super isn't much more or I'm in a hurry than I use that, if not I'll drop some injector cleaner into the full tank instead.

Previous thread which I linked the video and screen grabbed the BHP numbers here
What is everyone's opinion on premium petrols

Bl4ckGryph0n

The way Tesco creates it’s high octane option makes it depend on how busy the filling station is to maintain its effectiveness as I understand. I’ve had some really bad batches of Tesco Momentum in my tunes Golf R. So whilst it says 99 RON you don’t always get that. Both our Golf R and Mercedes AMG definitely prefer She’ll when using all its power. But if you live in a busy momentum area you can be ok.
No point putting it in an engine like that. It’s tuned for 95, giving it more will just be a waste and not benefit it.

dts_boy

So my BMW M140i will run better on premium/higher octane fuel then?
I've always run all my cars on standard/supermarket fuels and never had an issue.  I may give a high octane fuel a try but the cynic (cheapskate!) in me tells me fuel is fuel!