fuel

Gravey

Member
Hi sorry to ask what might sound like a daft question , but can you run a Z4 E89 23i on just normal 95 or can i put a higher octane in ? i'd like to run it on the good stuff if possible ? thanks
 
The car engine will be programmed for standard octane stuff, buying anything higher is a waste of money.

http://www.scientificamerican.com/article/fact-or-fiction-premium-g/
 
Avallon said:
The car engine will be programmed for standard octane stuff, buying anything higher is a waste of money.

http://www.scientificamerican.com/article/fact-or-fiction-premium-g/

Would you not have been better finding a report based on UK tests? Octane ratings and set ups differ across the world. There has been many studies done by which etc on the topic.

Fuel is now allowed to have up to 10% bio ethanol in it which for some cars can actually lead to drop in MPG but his usually effects lower capacity engines. 'Super' which used to be 97ron and is mostly 99ron now has additives which help boost the octane and have cleaners to help remove build up of deposits in the engine. 'Standard' fuel which is marked as 95ron can be this or like shell and Tesco 97ron so older 'super' rating.

It's each to their own, it can help the engine work more efficiently especially if it's had a build up of carbon deposits which can happen easily on a car that's maybe only done short runs. People can give their opinions but if you really want to know if it will do anything for your car other than lighten your wallet then stick a tank of it in next fill up and judge for yourself, however it can take a few tanks before its running purely on Super.

When you open the petrol flap it states 95ron so it's good for that but it's your choice at the end of the day.
 
Since most modern engines are direct fuel injection there is little cleaning done by the fuel. Maybe some benefit to the injectors but I haven't seen any evidence on that front.

I don't know how the 23i engine works but the N54 in the 35i will adapt to the octane value of the fuel.
On a stock car you will gain some power. That increase is much more noticeable when the car is tuned to run higher boost but on non-turbo engine I think the increase will be next to nothing.

There was a good article on pistonheads about premium fuel with dyno comparisons on two different cars. I can't find it now but the conclusion was out of all the UK premium fuels Tesco Momentum (99) was the best.
 
Both my wife and I notice the difference in pick up and drivability when we use Shell V-Power vs. standard supermarket fuel, so will always try and fill up with V-Power. We are running a 35i with ESS stage 2 though. We don't do too many miles so the overall running cost per annum isn't that different.
 
thanks , I've tried some higher octane stuff today i think i'll have to do a few tanks before i notice the change
 
R.E92 wrote.

"There was a good article on pistonheads about premium fuel with dyno comparisons on two different cars. I can't find it now but the conclusion was out of all the UK premium fuels Tesco Momentum (99) was the best."


Taking your advice a filled up the car with Tesco Momentum (99) and have just completed a 300 round mile trip to Liverpool and back.

Trip shows Av speed as 60 mph, not bad considering the Average speed cameras and 50 & 40 mph restrictions on the M6.

Car used as near as dammit 8 gallons, 299 miles covered. That's 37 mpg, well pleased with that.

HOWEVER. When I got some items out of the boot, I noticed the exhaust tips were really sooty, is this the norm or should I be getting this looked at?
 
This question comes around a regular as Christmas and usually ends with the same answer.

No definite answer either way!
 
Alpine Z said:
HOWEVER. When I got some items out of the boot, I noticed the exhaust tips were really sooty, is this the norm or should I be getting this looked at?

I would expect some sooty marks round the tips, the fuel mix is rich plus contains cleaning agents which help remove any deposits from the engine and its just carbon. Nothing to worry about unless it oil
 
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