GolfGTIforum.co.uk
Model specific boards => Golf mk4 => Topic started by: manz on 16 February 2005, 21:42
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I have gti 1.8t and using normal petrol currently and have been told to use Shell Optimax!! What does this petrol do for the performance of the car.
What is the Best oil to use on my car
Manz
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optimax is 99 RON (Research Octane Number)
the higher the RON the higher resistance the fuel has to spontaneously self combusting (known as Knocking). By using optimax, the onboard computer can run a more advanced ignition thus giving you more power.
*HOWEVER* it is likely that normal UK 95RON unleaded will allow you to run the same (or very close to) advance on the ignition so the difference in power is very small.
A bit of an aside but diesel fuel is classed on cetane number, the higher the cetane number the more likely it is to self combust. Just in case anyone wanted to know!
As far as oil goes, if you leave your car outside overnight I would recommend Mobil 1 0w40. It has a zero rating so it is runny even at low temperatures. This allows the car to have reduced frictional losses from cold, gives you better fuel economy on short journeys, and allows the engine to heat up faster. I believe it is also vw 505 rated. Downside is, its dear ?25 a gallon.
hope this helps
have a nice day
sv
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Ive used that petrol before, i didnt notice any difference other than its more expensive lol :laugh:
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lol - you're not wrong there ! :laugh: It takes two or three tanks full until you would notice any difference (so they say), I used to use it but it got to 10p a litre more than unleaded by us at one point so I went back to normal unleaded, to be honest I didn't notice much difference either.? :undecided: Can't see much point in spending more on fuel when you drive round and about town mostly, although Optimax is supposed to clean your injectors etc as it goes through your fuel system.? :smiley: