petrol normal unleaded or Premium?

paul1969 said:
I'm new to this I have only ever read the forums that other's have posted so this is my first lol.

I own a SDrive 2.5ltr which is a 2011. I've owned the car for just over 8 months and at the moment I'm just using normal unleaded fuel from my local Morrisons supermarket and have since buying the car.

Can anyone tell me if I am doing the right thing or should I be using a higher grade fuel and if so any recommendations to which one would be much appreciated.

Thanks!

My first Zed was the baby 18i E89. I started off using standard 95 from whichever petrol station was closest then, after reading something on the interwebz, I tried Tesco Momentum 99. The improvement in range was remarkable, going from reading around 360 miles for a tank to 410, mixed urban and extra urban driving. I definitely felt an improvement in the engine response too. I now have a 35is and have used premium from the start so can't say if the difference would be as marked as before. If there isn't a Tesco when needed I'll go with VP or Ultimate, but never bog standard juice.
 
With adaptive ECUs the higher octane rated fuel will give you increased performance as the ECU can advance the ignition timing more, particularly at higher revs, without the onset of knock. This will be much more noticeable with turbocharged engines. This does mean that the engine can run more efficiently and for the same driving style/speeds should give better fuel economy. Whether the increased fuel economy offsets the increased cost of the fuel is a very moot point!

For the lower power engines it can up their game a bit and be quite worthwhile. Having said that I don't use super unleaded in the 35is as it has more than enough 'real world' performance on 95RON fuel i.e. It is not required to use WOT that often when the higher RON fuel would come into its own and on the public roads I don't need any more performance! On a track, however, it would be a different matter.

Premium brand fuels do contain better additives, to help keep the engine clean, over supermarket fuels. Their RON is absolutely no different so will not produce better or worse performance. Any perceived smoother running is, I'm afraid, just that - a perceived placebo affect unless the enigine has been run for a considerable time and consistently on one or the other where the cleaning ability of the premium fuel can take significant affect. I run my Range Rover on supermarket fuel as it is a real gas guzzler and the overall fuel cost are a lot lower than using premium fuels. I do run an injector/fuel system cleaner additive through it every 3k miles though - the big V8 still purrs like a kitten.
 
There are many threads re this subject on this forum and unfortunately none have come to a proper and definative conclusion !
 
ronk said:
There are many threads re this subject on this forum and unfortunately none have come to a proper and definative conclusion !

Garvin's reply above is pretty close to reality, I suspect.
 
Different fuels must make a difference. I filled up my bike on Esso unleaded and it ran like a pig for the next 80 miles on a run until I topped it off with some Nitro. Ran smooth as silk after that. Totally put me off their unleaded.
 
flybobbie said:
Different fuels must make a difference. I filled up my bike on Esso unleaded and it ran like a pig for the next 80 miles on a run until I topped it off with some Nitro. Ran smooth as silk after that. Totally put me off their unleaded.

Different fuels do make a difference mate, as posted above by several members explanations.

The top and bottom of it is you get what you pay for, higher end fuels can increase fuel economy and performance, how much by can vary with certain cars seeing greater results...
 
Tried Shell V-Power this week filled up Think it was about 5 or 6 quid difference to what it normally costs me, To be honest it just seems to drive the same as before as when Using normal unleaded.

As for the performance with I can't really say on that because if I was on Top Gear I'd be James May.

Think I'm going to keep using it tho, if for nothing else but to keep the engine clean.
 
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