Top tier gas : Healthier for your car ...

[Kaotic Lazagna]

Originally Posted by 07liftback

I might be an outlier here but tried shell a few times since t-mobile Tuesdays had promotions for $0.25 off each gallon at shell.

I usually fill up at Costco but with shell, The torque felt about the same on my 5 speed yaris but my mpg dropped from 34mpg to 30mpg. I tried filling up at different shell stations with the same result. I can maintain about 34mpg with chevron gas but I just can't figure out why my mpg is much less with shell.

The 76 near my house produced the same results as well.

I've been using Shell since I got Dory (December last year). Before I switched wheels and tires, I was getting 43-45 mpg. After switching wheels and tires, it went down to 40-41 mpg. However, I'm not sure what Shell did, but my last tank dropped to 37 mpg. Tried Chevron (I used to use nothing but Chevron with my first Yaris), mpg was 41. I filled up with Shell again after, and I need to fill up again tomorrow, so I'll see what the calculations come out to. If it's lower than 40 mpg, then I can probably conclude that Shell did something with their formula here in the Bay Area.