On my last tank I noticed about 3 more MPG with Shell regular. I normally run Chevron regular and noticed a dip with winter of about 3-4MPG, pendign on how many short trips I do. I filled up today with Shell again today and will see when the tank runs out. It seems I get more MPG with Shell than Chevron. I live in the SF Bay Area. Anybody else notice it around here as well? We obviously don't deal with extreme cold. Maybe Chevron uses winter mix and Shell don't inthese parts??
<div class='quotetop'>QUOTE(bulldog @ Jan 9 2007, 12:09 AM) [snapback]372906[/snapback]</div> Funny you should mention that! I found the same thing but I always use the same two stations a Chevron in Daly City (only used when I wash the car), and an independent station that used to be a Shell station near my house, this is really our preferred gas station, they still buy from Shell, or at least they used to. One station doesn't make a pattern but I was always curious why our local station does better. I just assumed it had more to do with the actual pumps being different pumping 'speeds' or something like that. BTW I notice the difference year round for these two stations.
<div class='quotetop'>QUOTE(bulldog @ Jan 9 2007, 12:09 AM) [snapback]372906[/snapback]</div> I switched to Shell when I got their Master Card for the rebate. Previously I'd buy the cheapest gas I could find. With all of the varying factors I can't pin fluctuating mpg on any one brand.
Very interesting!!!! I just drove about 750 miles in a week for work. 5 trips to atlantic city & back. similar conditions on all trips but 1 was very windy. filled up once with shell and got the higest mileage. not a huge diiference, but it was higher.
I only pump Chevron or Shell 87. Shell typically renders me slightly higher mpg, but no Techron? It should have enough detergents since it's from Shell...(right?).
On my 3rd tank of Shell now and it definitely gives me 1-2 MPG more than Chevron. I will switch back to Chevron in a while to see what happens. Problem is we have had some really cold weather around these parts for the last week or so. Once the weather settles and I can get a consistent MPG reading with Shell I will switch to CHevron again to see what happens.
Independent of this thread I have also started a Shell trial, and while it's too soon to tell definitively, it's looking good for Shell. I'm guessing 2-3 mpg.
I'll switch to Shell too and see what happens. Any suggestions as to which octane to buy? I use to buy only Chevron for my trade-in (Nissan Murano) and I found that buying the 91 octane was cheaper per mile than the 87 octane. The owners manual for the Murano suggested the 91 also. Fortunately/unfortunately filling up the tank happens so infrequently with the Prius this study may take a while!
I just use regular (87). On my second tank it still seems to give 2 MPG or so more. It has been very cold and I had to run a number of very short trips, but still better than with Chevron.
Put in Shell for the first time the other day. So far, based on displayed mileage, mileage has gone down a few tenths. But, there are so many variables that affect mileage I guess it's really too early to say one way or the other.
Since 1989 I have not purchased Exxon gas, so I don't know what kind of mileage it might provide. I have sensed that Shell does provide slightly better mileage, but I don't know why it might make a difference. It could be the amount of ethanol that they are using, but due to the cost, I'm sure that all the distributors are only using the minimum required amount. Just short of using a dynanometer, I'm not sure how someone could accurately test the mileage; as others have said, there are a lot of variables that would happen during normal driving.
I've noticed that shell gives me better MPG than Chevron. and Aarco is a lot cheaper than Shell but I find the cost per mile is almost identical.
I believe in the Chevron product and can't really comment on the Shell product. However, here is a link to an excellent article published by Chevron explaining fuel economy and how it relates to gasoline. The end result is that there is variability in MPG between batches of gasoline and that the differences observed could very well be within the error band of uncertainty. Either way, the article is superb reading. http://www.chevron.com/products/prodserv/f...n/fuel_economy/
I keep track of my fuel economy at www.austingasprices.com. I don't drive a prius, but over the past year I've gassed up at mainly Shell, but also Exxon, 7-11, and HEB. The verdict, no significant or insignificant change in gas mileage from using one or the other. The highest mpg for the year, excluding the road trip, was 27.90, during the summer in June, and the lowest was just last week, which has also been the coldest week in the past year, with me getting 25.12.
I think the difference will really depend on a region by region basis, pending the plant where it gets blended. So far it looks like my 3rd tank on Shell here in the SF Bay Area will give me at least 2 MPG more than Chevron. This might very well change again in the summer. However it seems I'm not the only one who notiiced this by the responses on this thread.
<div class='quotetop'>QUOTE(John in LB @ Jan 24 2007, 07:37 AM) [snapback]380038[/snapback]</div> I've been filling up w/Shell a lot because of their Shell Mastercard rebate (5% credit when buying Shell gas towards future gas purchases; you got 3x rebates for the 1st 60 days yielding 15% credit!). I haven't noticed any significant difference in fuel economy between brands. Yes, that article is most excellent. That should go in a Prius knowledge base area or be part of a sticky!
