Premium Petrol or not?

[mk7gti]

I've been driving 2.0 TSI cars for eight years and after two years of trying 98 and 95 RON I decided I couldn't tell any difference.  My GTI is happily running on standard unleaded.

When driving on 98 RON I always felt the placebo affect was kicking in

[monkeyhanger]

If the car is set up optimally for RON98 then it'll run better on it than 95. Some previous VWs stated that they ran optimally on 98 and could run on 95 with slight reduction in performance, but current literature doesn't state that. Seems then that the GTI is set up for 95 and using 98 is just a waste.

[GTI7me]

I agree with you MonekyHanger.

I usually use standard shell unleaded. However i had a voucher for their Nitro+ so i used it for a couple of tanks (around 800 miles) to see if i could notice any difference in power or economy. I noticed no difference at all. I'm back on standard unleaded now. I realise that a dyno may pick up slight differences in power. I however could not.

J

[JoeGTI]

I'm confident it makes no difference and you are wasting your money with the "premium" stuff. I'm a cynical fecker at the best of times and it wouldn't shock me if the premium came from the same tank as the regular!
I think we're all guilty of persuading ourselves a product is "better quality" especially if you've just paid a premium for it.

[arcamalpha]

There are two separate questions. One is whether the fuel itself is any different (and therefore beneficial). The other is whether the mk7 gti (or gtd for premium diesel) can take advantage of it.

[Hawaii-Five-O]

Not this old chestnut again

Run it on 95 RON.

Anything else is waste of money.

[2014GTi]

I guess everybody is entitled to their opinions, magazines and independent tests have proven the benefits countless times in the past.
Better octane fuels combust better, simple fact 

[monkeyhanger]

Better octane fuels combust better, simple fact 

Only if the car is optimised for it, which the current GTI is not. 98RON fuel on a car optimised for 95RON will not help it run any better. The 98 will be combusted earlier in the compression/ignition/combustion cycle than would be optimum -most likely leading to same mpg at best. Higher octane fuel Ian't necessarily more calorific, it cab be compressed further before igniting, preventing pinking under the higher compression ratio that you would expect 95RON fuel to pink at.

The GTI has a compression ratio that lends itself to running best on 95RON, older engines set up with a preference for 98 have a higher compression ratio.

[Poached]

I thought the ECU could adjust ignition advance according to the fuel.

The benefits when tuning are well documented.

[Jimmgc51]

I thought the ECU could adjust ignition advance according to the fuel.

The benefits when tuning are well documented.

+ 1

I thought that too on the fuel cap it states 95 or higher it can run on 95 but the timing will be retarded by the ECU to allow the engine to run optimally on the fuel it has avail, so putting in a better fuel will allow the ECU to run on the best mapping it has available.

I use Shell Nitro pretty much all the time now since the new engines gone in and can I tell a difference in performance??

Not really but it's only an extra £4-5 per tank and I DO get more miles out of it on the motorway. I have actually tested this umpteen times and can range an extra 30-40 miles per tank.

HOWEVER - this is driving driving like a granny at 70-75 as soon as you plant your foot down any gains unfortunately have gone out the tail pipes!

This is from my personal experiment anyway but as said for the little price it is I'm happy to pay it knowing that the engines running at its best performance..