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My ej22 lseries does about 450 kms to a tank in the city, more on the highway. I do find it changes depending on the brand of petrol i buy, Caltex seems to be the quickest consumed, buggered if i know why... but it does. Has anyone else made similar observations?

Petrol with more ethanol in it burns quicker, and therefore you use more of it. So Caltax may be putting in more ethanol than others or it may just have a higher octane rating.

yeah i've found that my car seem to be that little bit better when i use either BP or Shell using the 98 ron fuel.yeah wasn't sure why either but LTurbo has cleared that up now, thanks.
whats the go with ethanol anyway is it bad for our cars or not. burn at the same temps, fuel consumption better or worse

I have found that the subi gets about another 50k's from a tank using BP ultimate.

Mike

Re: ethanol

Petrol companies can't use it unless they specifically say so at the pump. Ethanol is a good fuel, but you do use a bit more of it, so you need more, a little like LPG.

The variation of fuel consumption within the same brand and fuel type is big enough as I have found, for my years of experimentation and only using Shell brand fuel (excluding 4 or 5 occasions) I have come to realise that for the cars I have driven (L-Series and Liberty) there is no significant difference between 98 Octane premium and regular unleaded in the stats (only that it is more responsive on premium and with the L you can advance the timing which works well, but also uses more fuel too).

The only way you could test anything like this effectively and in an unbiased way is to travel the same distance and conditions day in - day out for quite a long time, you're looking probably 30 or so tanks to get decent figures and a useful average. Those that do this type of commuting would be good testers. But it's no small experiment. Unfortunately I don't do tat kind of driving, I do 30,000 to 40,000km a year but not generally the same roads / times / mood etc.

Also, fuel blends from refineries (I think there are only 8 refineries in Australia) actually differ from season to season.

I reckon you'd find next to no difference between brands but perhaps some difference between different fuel types, depending on the tune state and tune-a-bility of your vehicle.

Some interesting reading can be had from links from this page:
http://www.shell.com/home/Framework?sit ... _0116.html

Wow thanks all for such comprehensive responses!
You know SUBYDAZZ I think you are on the right track.... MOOD is probably the most significant influence to my consumption.
Need to chill behind the wheel me thinks 8O

When I get around to putting my desktop PC back together I will post a link to my updated fuel stats. (Shell Unleaded and Optimax)

yes thanx for the answer SUBYDAZZ, has given me a better understanding on the whole ethanol subject

OK, I updated my fuel stats for those who are interested:

The Subaru Shrine

or direct link:

here

Interestingly enough Today tonight did a test with 4 identical cars filled with PULP, ULP, 5% ethanol blend, 10% ethanol blend. Each car was totally drained of all fuel then a 5 litre measured quantity of each type of fuel filled into the tank. The cars were then driven around a course with the objective of driving as economically as possible until they stopped. Guess what order they stopped in?? PULP, ULP, 5% blend, 10% blend. The 10% blend drove for 40 minutes longer than the PULP.

See: http://seven.com.au/todaytonight/story/?id=24813

Make of this what you want, but it surprised me 8O

I agree that there is more at play...

I ONLY ever used Shell Optimax, well untill i moved over here. The RX DOES NOT like the other 2 brands of fuel (Gold or Ultimate) but i have no chioce