Prasius

iTrader: (1)

Okay - two graphs of my car. The first below was from a run on 10 January this year. I'd only had the car for a week, I was running it on Tesco 99.

291.9bhp / 300.0lbft



The graph below. After the January run I swapped over to running on Shell V-Power.

296.7bhp / 295.7lbft




The temprature/conditions were pretty much the same on both days.

I will keep my opinion of the graphs to myself until I've had some replies and opinons from others!

Minitrue

Imprezas seem to be extremely sensitive to fuel, more so than any other model Ive seen; and they dont all perform well with the same brands.....

Pete

What year, model is yours???

Prasius

iTrader: (1)

Knew I'd forgotten something!

MY02 STI Prodrive-style with PPP. Otherwise standard.

cw42

iTrader: (1)

291.9 v 296.7 = a 4.8 bhp difference

300 v 295.7 = a 4.3 lbft difference

I don't use Tesco 99, it's still not available around here , but I don't see the problem here, both running pretty much the same power, less than 5 isn't going to be noticeable is it?
I'd have thought the v power would be doing your engine some long term good though, at least if you believe the hype about its cleaning properties, which I do

You've still got an ugly car though

Prasius

iTrader: (1)

Just jealous yours dosen't look as nails

Its not the peak figures I was really looking at - look at the actual curves. The V-Power one shows the car holding near peak power and torque for a fairly considerable time longer through the rev range than the Tesco 99 does. The Tesco99 hits the peaks and falls off pretty quickly, the V-Power holds the figures higher for a good 600rpm.

Alan MaC

Very interesting.

Do you ever put octane booster in and, if you do, any noticable difference?

4-5 Brake on a day when you are up against
something "interesting" could make the difference? I don't know.

Good post.


Alan MaC

Prasius

iTrader: (1)

Just updated the graph from last week to the correctly printed one.

I think the difference in the curve profiles is even more obvious now. Hard to tell retrospectivly, but I'm sure what the graphs illustrate would be a fairly significant "real world" difference in performance between the two fuels that the numbers by themselves don't reveal.

Any experienced mappers/tuners opinions on this would be very appriciated.

bob r

iTrader: (46)

I am a very inexperienced mapper/tuner and I am not having it that the ambient temps were similar. This would surely be a factor.

Prasius

iTrader: (1)

It was pretty nippy both days - temps around about 7 degrees or so. The conditions were as close as you'd ever get doing runs over a period of time.

Snazy

Torque seems to peak a lot sooner, but is erratic too.
However, the power at the wheels peaks later...

How bizarre.