The PH article contradicts the 5th gear test in finding that that the biggest gains were with the lowest performance car. The 5th gear test found that for the highest performance car - the sti, gains were startling in both power and torque the lowest power one showed absolutely no improvement. The 5th gear test was done more scientifically so its the one I would believe. Would have liked to have seen a few more contenders and a comparison with regular ul as well.

 

I use BP Ultimate 100ron in my MY00 scooby and it hates it on full boost hard acceleration but saying that it acts the same on optimax V-Power aswell.

normally round town and under normal conditions it is ok but if you floor it on the autobahn and hold it right up the rev range the boost gets to 1.2 then drops to 0.4 then upto 1.2 and so on until you change gear, this does this in all gears even hooning in 5th it doesn't like it.

So if you think your cars would run better on 100ron fuel then you would be wrong.

 

So was it 95 ron supermarket fuel they tested then, not 97 ???

I cant tell any difference between Sainsbury's 97 SUL and optimax in my std 05 WRX to be honest, although I tried Tesco 97 SUL (not 99 as they dont sell it here !!) and thought the car felt a bit sluggish.

Have tried BP Ultimate and cant feel any difference either.

 

I'm not sure if a standard WRX MY05 can advance the timing for higher octane fuels?

Not saying it doesn't just enquring. Would be useful to know rolling road output from an owner with a WRX feed only on Optimax?

 

that's what I thought as the Golf was down on power as well (170bhp) I think.

I thought to myself, OK so the power is down, must be because they are measuring at the hub, but also thought that the transmission losses between the scoob and golf were on a similar scale and bearing in mind that the Golf is FWD and trasmission losses are quoted as a %, the scoob came out ok

really glad to know that all that money I have been spending on Optimax had some justification, shame they didn't put Tesco 99 in as well

 

The dyno is merely a comparator, with various 'standard' ways of quoting power, with atmospheric and at-the-flywheel conversion factors (read: approximations). Side-by-side comparison is what it's useful for, period.

The 5th gear comparison sounds either very stupid or rigged by Shell/BP. They compared 98/97 Optimax/Ultimate against a 95 (which just happened to be from a supermarket) on a car that's timed for 97, did they not? On 95ron the car's sensors detect knock and it adjusts to produce less power. No ****, Sherlock...

Optimax/Ultimate/Tesco99 comparison would have been useful.
What they did was not useful.

Andy

 

My 2003 STI was supplied with a full tank of 95Ron by the supplying dealer,But after seeing the 5/G report i want to start using 98 Ron.
Will the ECU automatically detect the higher rated fuel or will i have to reset it by disconnecting the battery as one of the other threads suggest.

Spikkey