Different Gas stations affects MPG?
 

I notice that some different gas stations have different quality gasoline. I know for a fact that with Shell they add a techron additive to premium gasoline. Anyone notice the difference in MPG when using different gas stations?

I own a Supra and I know for a fact that different gasoline affects its performance but I'm not sure about MPG?

one of the things I've noticed is that gas stations seem to all fill the tank to a different level. I only fill until it clicks off, I don't top it off. So that would affect your mileage if you do the trip odometer/gallons mpg method.

In my '88 Escort, Texaco seems to give better FE than BP. Those are the only two brands that I have used in about the last year in that car so I don't know whether other brands would effect mileage or not.

As long as you are not doing short fills that should not make much of a difference, and the average of a few tanks in a row will even it out. I think the biggest difference would be if some stations in your area sell ethanol blends, and others do not. Mostly the additives in the gasoline are detergents to clean your fuel system. Over the long term keeping a clean fuel system may enhance mileage, but straight out one tank to the next detergents should not make a noticeable difference.

Years ago my old Bonneville wagon would run like a bat of hell on Chevron, and poke along on 7-11 gas. At the time ethanol fuels were not mandated in my area. 7-11 was an ethanol blend, and Chevron was not. I'm sure this was the difference I experienced in my performance.

before ethanol was recently, fully integrated into local gas stations here, i believe chevron and shell yielded the best FE(for our cars).

there are many variables including additives(quality of fuel), shut off point, inclined/declined pavement, and pump accuracy to name a few.

some believe performance and economy are directly related.

Over 30+ years of driving many cars and motorcycles...I've never noticed significant differences between brands of gasoline. On my gaslog here I have been noting the stations where I buy gas just to see if there is a difference...so far I do not see any.

Back in the '60s, in our Corvair station wagon, Shell regular would run fine, other brands would ping. Any gasoline purchased outside California seemed to work OK, also.

Used a discount independent to fill my tank on my last entry on the log. It sputtered at the 590 mile mark. I then filled up at a shell station am getting 10 more miles at the first hash mark. I fill up to the top of the filler tube every time so i know it is filled up. Later on i may go back to just putting 5 gallons only.

I fill up at one station no matter what the price is. The topography is such that on one side of the pumps the ground slopes downward from them. If I park the Honda on that slope and fill it up, I can put more fuel in it than I can if its sitting on flat land. I sometimes sit on the hood to get the left rear up in the air higher too.

There are many things that can and do affect gasoline quality, such as time of day per instance... When the tanker truck last left, this usually stirs up sediments for up to two hours, how much traffic the station has (more is usually better in the sense the fuel doesn't sit in the tank too long then again the tanker has to come by more often).

And so on...

I started eco-driving only since a few weeks on my manual 11 years old diesel, so I don't have a lot of data to backup my saying. As I have a diesel I tried to change gears before 2000rpm, but then I was under 1500rpm and the ICE wasn't happy...

Before eco-driving I was using half low-grade and half mid-grade diesel. I changed to high-grade diesel and felt a noticeable change after half a tank : the ICE wasn't so unhappy to be under 1500rpm. After 1.5 tank, now the ICE can accelerate from 1200rpm :thumbup:

High-grade diesel contains different additives than mid-grade and this is certainly a better cleaning additive that is permitting my ICE to run better at lower rotation. Even if high-grade is 6% more expensive, I calculated on the first tank each km cost me 9% less :thumbup:

Currently these two high-grade tanks are permitting me to have a better mileage, but these are in fact doing a better/complementary maintenance than my mechanic is doing.

In a few tanks I will come back to low/mid-grade diesel and monitor how the ICE runs at 1200rpm to know when to have a couple of high-grade tanks.

Have fun,

Denis.

I was talking with a friend from work about how his car is running poorly. He told me he fills up at Cosco because of the cheaper fuel.

In my area we have Maverick, Flying J, Cosco, Sams, Conoco, Chevron, Citco, Shell Tesoro and Sinclair. My advice to him was to fill up at Chevron, Shell, Citco or Conoco based on my experience with my 2001 Chevy Impala. If I used Maverick, Flying J, Cosco or Sams I would expect about 25-50 miles less on a tank. In addition the car would misfire at idle with this cheaper fuel. I also seemed to get a smoother idling engine running 87 octane accept at Chevron where I could have the same result with 85 octane.

Unfortunately my wife fills up wherever is convenient. She has been driving the car for 3 of the 6 years I have owned it and I have had to replace the fuel filter every year until she got her Jetta TDI. I have also had problems with occasional engine surge that the dealer couldn't isolate that went along with the fuel filter replacements. Surprisingly adding a bottle of Amsoil Performance Improver Fuel Additive at 201,000 miles and the problem has gone away. Needless to say I was totally impressed with the results especially when the instructions on the bottle said to use it every 4000 miles.

Groar, Where do you get different grades of diesel? In my area we have on and off road diesel and Sinclair carries B50 Biodiesel in the summer that runs the same but loses about 30 miles on a tank. Of course we also have winter diesel in the winter that kills economy.
In the summer my 8000 pound 95 Ford F-250 extended cab 4X4 gets consistent 19MPG shifting at 1500-1800 RPM with an occasional jump to 20 when I stay under 65 on the interstate. In the winter it gets 17-18.
I hope to get an extra 100 horsepower, 230 ft pounds of torque and 22+ MPG with an upgraded exhaust turbo and intercooler.

In fact the grade diesel may not be the correct term. It's mainly the default additives that make the diesel a low/mid/high grade.

In supermarkets the additives are minimal. They permit to avoid foam when you fill your tank (so they sell you more diesel at each refill), and optionally to mitigate diesel's odor persistence (to make you feel more ecological). Here is low cost, low grade.

In little stations and automatic stations you have a few more additives. Here is mid cost, mid grade. An example is Esso stations.

In stations with services, the additives are more important and should permit you to never have to add additives such as injectors cleaners. These are also compatible with next European norms such as low sulfur (10 ppm due for 2009/01/01). In these stations you have both mid and high grade. Costs are of course mid and high. In France there is only Total, Shell and BP.

Since a few months both my wife and I are using high grade and are seeing a better behavior of our cars. They have always been maintained as constructor's schedule. Now I can accelerate from 1200rpm while I couldn't stay at 1500rpm before that. The "holes at acceleration" disappeared on my wife's car.

Denis.

i'm going to presume that's not spam. so i'll defend that statement...

a local celebrity mechanic/consumer advocate recommends Amsoil PI as well. he believes it's one of the best fuel additives out there(as most are just a waste of $$$).

i've used it with good results as well. every 4k miles is debateable however. i drive mostly hwy miles, so 6 months or 6k miles works for me. depends on your application certainly.

I'm experimenting with a bottle of BG 44K in the beast's current tank.

-Jay

Techron is a registered trademark fuel injector/system cleaner owned by Chevron not Shell. So it wouldn't be in Shell gas unless Shell bought out Chevron lock, stock, and barrel, patents and all. It is in all grades of Chevron fuel and is part of Chevron's patented additive package.

Branded gasoline mostly comes out of the same pipeline so it starts out all the same. Then each Brand ads their own additive package to the gas. That is where the difference is. All major brands have their own (secret and patented and hyped up as better than the other guy). Which one is really better?? Who knows.......

As far as non name brand gas goes, you have no idea what you are getting and I am sure there is a difference between that and a branded gasoline. Then, after that, there is probably ethanol in it in areas where both ethanol blended and straight 100% gas is available. Generally, you get what you pay for in quality. (or in the case of gas, what you pay too much for)

Personally, I pretty much stick to name branded gas and avoid the others unless it is an emergency.

With the exception of Chevron diesel is competitively priced here and I can't tell the difference in FE like on my gas cars.

The nice thing about my Ford is the tanks are 16 and 17 gallons so I know if I get 285 or more miles to a tank I am getting right at 19MPG.

I have run fuel additives with no effect on economy. Cetane boost quiets the engine and helps it start better in the cold.

I have read in some of the diesel mags that low sulfur diesel has killed power and economy.

In Europe the minimal cetane index is 51. After a little research I found that Total has 52 for its mid-grade and 55 for its high-grade. This index is partly boosted thanks to an additive called procetane. High-grade from Shell and BP also have a cetane index of 52.

I read in some french forums that some third party additives for diesel contain procetane.

Denis.

Your EVAP system does not like this one bit. Just an FYI.