Differnet gas nets 10mpg gain

Does Shell's best have 10% ethenol in it ? ..That's the biggest mileage killer ...maybe they use it in the cheaper grades ??

 

I've used Union 76 the last few weeks and have noticed a marked increase in my MPG. It's no fluke either. I had to get a tank of mobil in between this week and my MPG dropped 4 MPG. I refilled with Union 76 and it shot back up again. Based on the OP's post, I'm tempted to try the premium grade too.

 

I have found through a lot of driving, 126K+ on 2006 Prius, that using premium tank after tank doesn't really help your MPG's but using it every 3rd or 4th tank does show a marked increase. In this kind of app it is almost acting as a "cleaner".

I too have found that Shell gas especially the premium with the added "gunk" cleaner additives is the best of the premium brands.

As has been noted THOUSANDS of times before on other threads ethanol sucks and the 10% mix causes a 4-5 MPG regardless of the octane rating. My $0.02

 

The 64MPG question here is: Does anyone know what gas companies don't use Ethanol in the Summer?

 

it doesnt make any sense to use premium. its 30 cents a gallon more and even if you DO get more mpg's, you dont save anything because it costs more....

 

BP in Florida does not use ethanol in their gas.

 

I'd bet a dime that this experiment used one tank of gas each? It wasn't the brand or octane of gas, it was the details of the weather, the traffic, the route, and your driving styles on each of those tanks. And in any given region, if one gas uses ethanol to reduce air pollution, then they all do. Use 87 octane as recommended by Toyota in the owner's manual and don't worry about it.

 

hold on now pedro....i see your calculations however, i have been partaking of the knowledge and experience of many trusted posters and cant believe that out of the clear blue sky, somebody comes up with a statement and you take it for gospel. if it was possible to get more than 10 mpg's, i know someone would have told us about it before. i am willing to concede that maybe, just MAYBE, changing to premium might gain an extra 5 mpg's or so. i dont know. i never tried. i never read it on these forums...i am just saying maybe its possible. but i cant believe that you would gain 10 mpg G-U-A-R-A-N-T-E-E-D by switching to premium. my calculations were done on the extra MAYBE 5 mpg's. given its 30 cents a gallon more for premium, if i bought 10 gallons and spent $3.00 more and for that 10 gallons I got 50 more miles, and give that i get 48 mpg now with hopes of gettintg 53, it would almost be a wash. can you agree with MY explanation of calculation??

 

Wow, talk about elitist.

 

And where did you learn to spell, "Differnet"????

 

Here in Canada:
- Shell is the best
- Ultramar is / seems the same as Shell
- Petro Canada - AWFUL - lose 20% mileage

 

Problemchild is just that. A Problem child and a troll. I have found that the best way to take him is to ignore him as I do. Then you are a happy camper.

 

All other things being equal, premium fuel reduces mileage. Higher octane = less energy, right? Is it possible that your gas station's premium contains less (or no) Ethanol than the regular?

I put in premium once by accident, and the car couldn't get out of it's own way. It was like I'd put diesel in it or something. Mileage dropped by at least 5 mpg. It was torture to drive that tank, and I swore I'd never touch premium again.

 

'Problemchild" you were a little rough with "Tasker109" I think you bring a interesting point with the premium gas and I will test it out. I have read other threads that say the opposite but is worth a try. Thanks

 

Three comments:

1) I expected to get 10% less mpg when in Oregon where ethanol is apparently required by law. I didn't notice any significant drop in mpg even though I had to fill twice in that state. We were on a 3,500 mile trip from SoCal to Canada and back and my driving habits were pretty constant on the whole trip. I recorded my mileage and just didn't see any effect. I believe others have. I wonder why I didn't?

2) I tried one tank of high octane and didn't experience an apparent increase in mileage. For me I'll stick with 87.

3) I don't go looking for Shell stations but I've noticed a significant increase in mpg, easily 5mpg+, when filling with Shell. Interesting because I've avoided Shell most of my life after working on engines in the 50's and 60's. Any engine that regularly used Shell was loaded with carbon and residue. I suppose the formula today is quite different.

 

I always fill up at Murphey Gas in Arkansas which has ethanol added but during the recent rash of (wo in a row) hurricanes in Arkansas, they brought in fuel from another source. I was told it had no ethanol. I got 7mpg higher during my use of this gas. I drive 87 miles each day on a rural paper route, so didn't get to enjoy the non alky gas for long.... jf

 

Same in Canada - Shell gets me below 5.0 l / 100km, and Petro Canada 5.2 or worse.

I noticed it more in total km driven, with Petro Canada, I never get close 600km. With Shell, 620 to 630 when the last PIP turns off.

Same driving, same conditions.

 

How premium fuel affects your mileage depends mostly on your engine. If your car was designed to run on regular, you will probably not see any improvement with premium. And as some posts indicate, may actually get less MPG. espesially if it is an older car that does not have the ability to adjust your timimg and fuel mixture automatically.

If, however, your car was designed to use and recommends using premium, or can automatically adjust timing and fuel mixture, you may get an improvement in MPG.

You are correct, the octane does not add energy, but it allows an engine that is designed to take advantage of a high compression ratio, to get get more of the energy out of each ignition. Thus, the result is more HPR, or less throttle for to obtain the same HPR.

The difference may also vary due to driving habits. Agressive driving such as rabbit starts and high speed driving may actually find an improvement in MPG using premium over regular, if the car is designed to take advantage of it. However, a driver that accelerates slowly and rarely does any high speed driving, may notice little, if any, improvement in using premium over regular, even if it is recommended for the vehicle.

Not sure how you get your fuel where you are. Here on the east coast, for the vast majority of brands, it all comes through the same pipeline from the gulf. A difference does not exist until the additives are added at the storage depots. And as it was pointed out, these are detergents, etc., and do not contain energy, so should not affect MPG.

Ethanol is usually the last ingredient to be added, because of it's tendancy to absorb water. I personnally believe this may well be a likely cause of variations in MPG between brands or even between tank fulls at the same station. I am not comfortable with this part of the process or it's controls or regulations. There have been a number of articles siting variations in the ethanol % from independent testing, even above 15% in some cases. Sorry, don't remember the source.

Net is, that if the car is designed to use premium, while it mat or may not significantly affect gas mileage, it is better for the car in the long run. If regular is recommended, little if any benefit, or even degradation may result in using premium.

And, of course, the only way to know absolutely is to track your own results.