Since I've been involved in giving my opinion on the effect of ethanol on fuel mileage on these forums, I just had an opportunity to put my opinions to an informal test, just to see if I'm blowing smoke.
Yesterday I drove back from a work trip out of town. The drive back was about 469 km, and I started out with a full tank of Shell V-Power 91 fuel. Today, after a bit of city driving to run some errands, I had 1/8 of a tank left before I filled up again at 490 km. The highway part of my trip was mostly with the cruise control set about 5 kph over the speed limit, around 115, with a few faster bursts to pass, and one or two smoke breaks.
The last 30 km, roughly, was at around 130 kph. I really needed to take a leak.
By my calculation:
7/8 of a tank used @ 490 km
8 * 490 / 7 = 560 km
Therefore (assuming my fuel guage is halfway accurate), I should have gotten 560 km from a tank of Shell V-Power gas.
This more or less jibes with my previous feeling that I was getting better mileage with the V-Power 100% gasoline vs. the watered-down 90% gasoline.
The notable thing about V-Power gas is that it contains zero ethanol. Regular 87 octane, it says on the pump, "May contain up to 10% ethanol".
Of course, the real concern is what is the cost difference?
My experience is that if I got 500 km out of a tank of regular gas, I'd be damn lucky with highway driving. Most times it's closer to around 450 km. Other Ranger / B4000 owners can chime in here. But I'll be reeeeal generous and call it 480 km.
Sooo, the price at the pump when I filled up @ Shell this evening was as follows:
Bronze 87 "May contain up to 10% ethanol" -- 116.9
Silver 89 "May contain up to 5% ethanol" -- 125.9
V-Power 91 "Contains no ethanol" -- 130.9
Percentage price difference between Bronze and V-Power = +12%
Percentage mileage difference between Bronze and V-Power
480 vs. 560 = +16.6%
Premature and unscientific conclusion: Using the expensive gas actually saves you money. Although V-Power costs 12% more, you get 16% better mileage.
Also, since V-Power contains more additives that aren't useless and harmful crap like ethanol, you save money by not having to buy bottles of fuel system cleaner.
Disclaimer: obviously this is a just a casual one-off test, and it's not terribly scientific. However, if nothing else, my driving is pretty darn consistent (except when I've got to pee, then I pin it).
Also, don't drag in the red herring of fuel octane rating. That'll have no effect. 99% of engines are quite happy with 87 octane. The main point is that V-Power isn't watered down with magic David Suzuki treehugger fluid. It's 100% gasoline.
Let the sissy slap fighting begin!