[nds76]

After fueling my Cruze with Marathon gas (regular) with 52mpg remaining in the tank I logged 448 miles.

And after fueling the Cruze on my next fill-up with Holiday gas (midgrade) and is Top Tier, with 52mpg remaining in the tank I logged 483 miles.

The difference in mileage is negligible between regular unleaded and Top Tier midgrade. The results could be the gas or how I was driving. Thoughts?

 

[Tomko]

Not even remotely a scientific study.

Anecdotal at best.

If you had a way to accurately measure the amount of fuel used, you'd start to build some sunbstance. But then you'd have to consider A/C use, exterior temperature, etc. as factors to compare one against the other.

That's why epa ratings are done in laboratory conditions. So they can be repeatable and comparable.

FWIW the farthest I ever went on a tank on my Cruze was 752 miles. And that was running the A/C and driving through some terrible weather. But it is a diesel.

My advice is the same advice in your owners manual. Always run a top tier gasoline.