I'm sure this topic had been brought up before. A few years ago I found a site talking about top-tier gasolines. Most all brands of gasoline was tested for their detergents.

I know all base gas is the same. It's the additives that makes the difference. Top-tier gas can keep the injectors clean so they will perform at their best. This site tells about why use top-tier gas and also list the brands to use.

Be sure to read each link at the bottom of the site.

http://www.toptiergas.com/

 

See the Fuel Matters! thread on the Prius page.

 

Now I can see why you use shell. I found shell gave me a one mpg better than chevron. A few years ago I started using phillips from the new station in town. I picked up another mpg. I was figuring this using the scan gauge and also a calculator on a very level drive at the various pumps. I was then driving the '03 Corolla and that took me from 40 to 42 combined mpg.

So far i'm getting good results with the phillips in the TCH. I only have only 509 miles on it. It will take 4 or 5 tanks to get consistent.

We have one shell station here in town. There drive at each pump leans out. I can't stand that. There is a new shell mini-truck stop about 8 miles north of town. There about 15 cents higher on there gas.

Thanks much LOL TCH for the info you pointed me too.