Gasoline comparison

DetergentCandy · Post by **DetergentCandy** » Tue May 18, 2010 7:13 pm

I used to not care what brand of fuel I put in my car. It all comes from the same source for the most part. So why would it matter?

Different companies put different additives blah blah blah.
I would normally mix and match my gas. Whatever was cheapest/closest/convenient. Sometimes Shell. Sometimes Chevron. Sometimes Circle K. Alot of the time QT because it's always the most convenient.

My friend warned me about staying away from QT and most of the other cheaper gas companies. I guess their detergents are state minimum.

So, I decided to put the two top companies to a test.

Three consecutive tanks from both Shell, and Chevron.

Before, using whatever was convenient, I was averaging about 25 MPG mixed driving. 50-60% of that was usually highway.

I first switched to Shell. Each tank got me better and better mileage. My third tank of Shell gas, averaged me 32 MPG! That was mixed driving, about 70% highway.

I'm now on 1/3 Chevron tanks. Just filled up, so i'll update again when my light comes on.

I know there's other factors involved, besides just city driving versus highway driving. Especially since I did a bit more highway driving on my last tank than normal. But I still feel that the better quality gasoline at Shell, granted me far better gas mileage than the cheaper stuff I was putting in before.

slaw · Post by **slaw** » Tue May 18, 2010 7:49 pm

interesting study, id like to see how this works out for u
i personally try not to run anything besides sunoco

esfan · Post by **esfan** » Wed May 19, 2010 12:39 am

Since Chevron send me their credit card so I used Chevron all the time. Their Techron actually fixed my gas gauge needle problem for only a tiny little...(which means it points higher than before)

Midnight_Rider · Post by **Midnight_Rider** » Wed May 19, 2010 2:28 am

There is a depot for gasoline tankers across the street from my full-time job. I have seen tankers for Shell, BP, Speedway, Family Express, Pilot, Marathon and Swifty fill up at the same depot. Differences must come at delivery since all of these brands get wholesale at the same place.

dank(r/t) · Post by **dank(r/t)** » Wed May 19, 2010 2:37 am

i just know not to touch speedway gas, i usually aim to use shell, or bp

Midnight_Rider · Post by **Midnight_Rider** » Wed May 19, 2010 3:40 am

Speedway/Super America is owned by Marathon so they use the same gas. As I stated above, I have seen tankers from Speedway, BP and Shell fill up at the same depot here in my area.

BlackRoseRacing · Post by **BlackRoseRacing** » Wed May 19, 2010 5:42 am

KwikFill for me unless I'ts my R/T running E85. I stay away from Sunoco as my mpg in the daily driver drops horribly. Up here in WNY we don't have the options like you guys out of state.

Marcel · Post by **Marcel** » Wed May 19, 2010 11:24 am

Midnight_Rider wrote:Speedway/Super America is owned by Marathon so they use the same gas. As I stated above, I have seen tankers from Speedway, BP and Shell fill up at the same depot here in my area.

In the netherlands we have several regional gas ditribution centers, and basically all companies get their "raw" gas there. After getting it there, they add their mix of additives and that's what's making the 'difference' out here.

Dunno if it's really all that different as people say and the gas companies say, but i always fill her up with BP since it's on the road from work to home

fixitmattman · Post by **fixitmattman** » Wed May 19, 2010 12:30 pm

I doubt the outlet where you buy the gasoline is the actual problem. Despite the number of different stations there's only so many places to buy gasoline from in the quantities needed to run a gas station. I'm willing to bet it's the different amounts of ethanol and different attitude/driving style. That would affect things more than anything, along with the different driving mix you mentioned, or the temperature, etc.....

glasswars · Post by **glasswars** » Wed May 19, 2010 1:52 pm

Sounds interesting. I am 95% of the time Shell. If I can't get shell, it's either Sunoco or BP.

darthroush · Post by **darthroush** » Wed May 19, 2010 3:34 pm

In the Neon, I generally fill up at Safeway or Arco (BP) and average about 30MPG combined highway/mountain driving. Usually about 20-25MPG or so solely up in the mountains. It's been my experience each car reacts differently to different brands, for some odd reason.

OB · Post by OB » Wed May 19, 2010 3:58 pm

I think it's funny that people think different fuel brands are going to have a significant effect on mileage. The truth is, unless a true experiment is conducted in a controlled environment, mileage calculations are rough at best, and extremely inconsistent. There are too many variables involved, and a lack of means to factor in corrections for these variables makes this kind of thing a big joke. Just changing ambient temperature by 5-6 degrees is enough to void any attempt to reproduce similar results from one tank to another. One WOT slip during an experiment could probably make for a 2-3 MPG loss overall. Climbing an extra hill one day could easily do the same. Stuff like this makes these experiments a waste of time.

Marcel · Post by **Marcel** » Wed May 19, 2010 4:05 pm

true, true... same goes for hydrogen generators and/or adding acetone to your fuel... non-standardized test conditions + human = FAIL

OB · Post by OB » Wed May 19, 2010 4:06 pm

It's just silly that so many people out there take this kind of thing so seriously. One of those "forum monkey" myths I guess.

*Back to the real world*

Marcel · Post by **Marcel** » Wed May 19, 2010 4:33 pm

yeah i know

Too bad it is in dutch, otherwise i would most certainly post the e-mail traffic i had with a company who sells hydrogen generators and claimed 30% better mileage

they suddenly stopped, and not because of any foul language, they just gave up

darthroush · Post by **darthroush** » Wed May 19, 2010 6:24 pm

OB wrote:I think it's funny that people think different fuel brands are going to have a significant effect on mileage. The truth is, unless a true experiment is conducted in a controlled environment, mileage calculations are rough at best, and extremely inconsistent. There are too many variables involved, and a lack of means to factor in corrections for these variables makes this kind of thing a big joke. Just changing ambient temperature by 5-6 degrees is enough to void any attempt to reproduce similar results from one tank to another. One WOT slip during an experiment could probably make for a 2-3 MPG loss overall. Climbing an extra hill one day could easily do the same. Stuff like this makes these experiments a waste of time.

I just based mine off of filling the car up with ____________, driving the same way as always in the same weather, etc., what have you, and having the needle drop to E after 100 miles from a full tank, instead of my normal range of 250-300+...
I agree specifics are pretty much going to be almost impossible.

OB · Post by OB » Wed May 19, 2010 7:46 pm

Watching the needle is a total waste of time. It's meant to be used as a reference.

Every one of these cars has a 12.5 gallon tank. They get between 20 and 40 MPG. No reason to think about it any further.

darthroush · Post by **darthroush** » Thu May 20, 2010 1:17 am

OB wrote:Watching the needle is a total waste of time. It's meant to be used as a reference.

Every one of these cars has a 12.5 gallon tank. They get between 20 and 40 MPG. No reason to think about it any further.

If the only thing that has really changed is the gas and I get 200 miles less on that tank, it's not something I'm just going to shrug my shoulders at. A normal fill-up is 10 gallons for me. 100 miles would be 10MPG. I get that in my 5.8L H.0. 5,500 pound truck driving up hills. Worth thinking about to me I guess --> you think about things a bit more carefully when you don't have a job (income).

fusion210 · Post by **fusion210** » Thu May 20, 2010 3:20 am

One important factor would be the ethanol content of the gas you're using. E10 will get worse mileage than straight gasoline.

Midnight_Rider · Post by **Midnight_Rider** » Thu May 20, 2010 3:33 am

I've just tried to stick with BP or Shell (if BP wasn't available or Shell had a big cost advantage over BP). I did have to put Exxon in the car once on my first trip to Carlisle since this is where the caravan I was driving with wanted to stop.

INVUJerry · Post by **INVUJerry** » Thu May 20, 2010 7:18 pm

Even though they pick up gas at the same terminal, just as dutch neon said, they put their special additives in each tanker, that's what makes it different. I've used Wawa gas, and Sunoco, they are usually the most cost effective. If I'm trying to do a back to back MPG comparison, I go to the same pump for back to back fill ups. I've waited behind someone at a empty gas station to get to a certain pump.

NYG gets 33MPG on the regular, I'm so happy with it. I'm sure if I kept it under 75, it'd be in the 40's.

DetergentCandy · Post by **DetergentCandy** » Fri May 21, 2010 2:56 pm

OB wrote:I think it's funny that people think different fuel brands are going to have a significant effect on mileage. The truth is, unless a true experiment is conducted in a controlled environment, mileage calculations are rough at best, and extremely inconsistent. There are too many variables involved, and a lack of means to factor in corrections for these variables makes this kind of thing a big joke. Just changing ambient temperature by 5-6 degrees is enough to void any attempt to reproduce similar results from one tank to another. One WOT slip during an experiment could probably make for a 2-3 MPG loss overall. Climbing an extra hill one day could easily do the same. Stuff like this makes these experiments a waste of time.

Well then be glad that i'm only wasting my time, and not yours!

First tank of Chevron isn't going so well. But I blame mostly city driving for that. Had to run a lot of errands to and from stores and work. But that's fine. There was still 1/8 tank of Shell in there anyways.
I really only care about the third tank of Chevron. I'll make sure it's the same driving pattern as the third tank of Shell was.

heydockyle · Post by **heydockyle** » Fri May 21, 2010 4:50 pm

While Derek may have came off a little harsh, it's true.

You may be able to get "aroundabout" results. But nothing will ever be definite.

Post by **occasional demons** » Fri May 21, 2010 6:38 pm

fusion210 wrote:One important factor would be the ethanol content of the gas you're using. E10 will get worse mileage than straight gasoline.

Not really true.
With a carburetor/distributor controlling the spark curve, more likely, but the PCM can make up for it.
I have used up to 4 gallons of E85, and not seen much of a difference in miles than I usually get. 2 gallons E85 to a tank seems to actually do better than straight E10. If the PCM has enough spark advance available, it is going to use it.

Haganracing · Post by **Haganracing** » Fri May 21, 2010 6:55 pm

I buy gas at "sheetz" more than anywhere else.. Never have an issue.

esfan · Post by **esfan** » Fri May 21, 2010 7:47 pm

I'm not into any gasoline but I used Chevron credit card and I like the thing named Techron... and that's why I stick with Chevron. If I had a Shell credit card, then I'll probably go with Shell. Same thing applies to every gas companies' credit cards. Sounds retarded I know...

DetergentCandy · Post by **DetergentCandy** » Sat May 22, 2010 4:36 am

esfan wrote:I'm not into any gasoline but I used Chevron credit card and I like the thing named Techron... and that's why I stick with Chevron. If I had a Shell credit card, then I'll probably go with Shell. Same thing applies to every gas companies' credit cards. Sounds retarded I know...

Not retarded, no! I can get a shell card tomorrow if I want, and not even care about this test i'm doing. But my regular rewards card has better...rewards than the Shell card

DetergentCandy · Post by **DetergentCandy** » Mon May 24, 2010 4:57 am

Alright. Same boat as I was with the first tank of Shell.
25 MPG. Filled up for a second time with Chevron.
Countin' the miles!

DetergentCandy · Post by **DetergentCandy** » Wed Jun 02, 2010 7:16 pm

Second tank of Chevron - 26 MPG. That's 50% highway driving.
Third tank of Chevron - 27 MPG. That was 70% or more highway driving.
:/ Hmm...ya there's always different factors to consider, but i'm back to Shell.

Besides, filled up with Shell last night, and my check engine light didn't come on this morning

Paul56 · Post by **Paul56** » Thu Jun 03, 2010 8:59 pm

I generally try to stick with one of the retailers listed at this site:

http://www.toptiergas.com/

But, on my road trip to Texas I'm not always able to find one of those nor do I want to start searching for one when I just need some gas on a long trip.