My gas study

[Arya Stark]

For years I have noticed when I fill up at certain gas stations, I get less mileage but have never really measured how much I get to a tank when I fill up at certain gas stations. In my mind it was always CO-OP where I would get less mileage than other places.

So I decided to do 5 tests filling up at CO-OP and then 5 at Shell. I filled up 5 times at each place right after changing my oil. I did CO-OP then Shell and used the same pattern until I was finished.

I drive a 04 Honda Pilot and then marked my findings as soon as the gas light came on. Almost all city driving over about 2 months. Regular gas.

My first test was at CO-OP: 396 km

test 2 (Shell): 413 km

test 3 (CO-OP): 403 km

test 4 (Shell): 419 km

test 5 (CO-OP): 405 km

test 6 (Shell): 417 km

test 7 (CO-OP): 399 km

test 8 (Shell): 412

test 9 (CO-OP): 405

test 10 (Shell): 426

Even I was shocked at the findings. Not one time did I get more gas mileage filling up at CO-OP. I don't know who supplies their gas but it doesn't seem as high of quality as Shell. I will still probably fill up at CO-OP once in a while because of their full service, but will use Shell or another big name gas station more now.

This could all be coincidental obviously as well so take with a grain of salt.

[FireFly]

My husband and I found that when we used the premium shell gas, we actually get even better gas mileage by over 50k/tank.

[Knalus]

Did you record the octane of the gas you were filling up with?

[undercoverbrother]

So disapointed in the focus of your gas study

[Arya Stark]

Originally Posted by Knalus

Did you record the octane of the gas you were filling up with?

Yes, both 87.

[Arya Stark]

Originally Posted by undercoverbrother

So disapointed in the focus of your gas study

Why?

[undercoverbrother]

I thought we might be going into this area.........

http://forumcdn.calgarypuck.com/showthread.php?t=78948

[calgarygeologist]

So is + or - 5% range significant in the grand scheme of things?

[Arya Stark]

Originally Posted by calgarygeologist

So is + or - 5% range significant in the grand scheme of things?

Not really no, but an extra 15 km of driving is better than nothing. And besides better quality gas is better for the engine and possibly the fuel system.

[burn_this_city]

There shouldn't be much of a difference on 87, since all refiners are forced to blend 10% of their total gas pool with ethanol. Shell's 91 octane is the only gas available without ethanol, and you will see improved mileage vs a competitor's blended 91.

[Derek Sutton]

Originally Posted by calgarygeologist

So is + or - 5% range significant in the grand scheme of things?

Well lets rough it out.

Say he puts in 60 liters, I don't know how big of a tank a Honda Pilot has. So 5% is 3 liters @ $1.15= $3.45. Now depneding on how many times a week/ month you fill up it can be quite a difference or euqate to less then $10 a month. But all the "reward programs" would complicate things, I don't know how to convert air miles to Co Op member refunds.

[Looch City]

Did you also record the exact amount of gas you filled each time? If you take that and divide it by the range to get the L/km average, that should show you how significant/insignificant the difference is.

[Chill Cosby]

Did you record the price difference and include those sweet grocery bucks you get at CO-OP?

[GGG]

I would suspect the auto shutoff point on the brand of pumps they use is set differently then any inherent difference in the gas. 10-20k difference is 1-2l per fill different.

[burn_this_city]

Shell's fuel overall is higher quality than other brands because the Scotford refinery has a more advanced hydrotreating process for upgrading oilsands feedstock. Their diesel fuel is definitely superior, but I'm not sure what the difference on the gasoline side is.

[Derek Sutton]

Originally Posted by GGG

I would suspect the auto shutoff point on the brand of pumps they use is set differently then any inherent difference in the gas. 10-20k difference is 1-2l per fill different.

True I know one place I go to I can get another 7 liters in the truck after the pump kicks off, way more then when I get gas at Canadian Tire

[ken0042]

Did you run the tank dry- to the point of your car stalling because it ran out of gas? Otherwise the margin of error is in your gauge.

That is why using MPG or L/100 km is a much better way to measure as opposed to distance "per tank."

[DownhillGoat]

Two problems. One, as pointed out, you're going total km, not l/100 km. Absolutely no way to tell if you're using the exact same amount per tank, and extremely unlikely that you are. Two, is that as far as I know, CO-OP, much like Safeway, Can Tire, etc. Don't always get their supplies from the same place. I've seen various trucks refuelling the Safeway tanks in Cochrane.

That being said, I too have always found better anecdotal results with Shell, and use the 91 exclusively from them on my vehicles that require it, due to the lack of ethanol.

[PsYcNeT]

It might be because Shell is the only vendor that doesn't use E10 fuel, which by dint of simple physics, offers less mileage than non-E10 fuel.

[burn_this_city]

Originally Posted by PsYcNeT

It might be because Shell is the only vendor that doesn't use E10 fuel, which by dint of simple physics, offers less mileage than non-E10 fuel.

Only V-Power is ethanol free.