I have a 01 surburb wht type of fuel is recommended to be used

 

regular unleaded. Use of higher octane fuel would be a waste of money and provide no increase in mpg.

 

try a top tier fuel and or use techron to clean

 

That used to be my exact words as well...however with gas gas prices plunging to nearly free , I have started using premium based on some findings that 73Shark did, and all be darned if MPG does in fact seem to improve somewhat with premium you will need to do your own cost comparisons to the cost vs mpg improvements but in some conditions it could be a win win..
In short day to day city traffic probably no benefit but on the highway or at least longer drives, I think there is some improvement..
I suspect it all has to do with alcohol content in each grade...

 

Imo it has more to do with the individual engine comp ratio and tuning than the fuel. It will vary depending on the set up. That's the great thing about knock sensors

I agree, test it out. My low hp family sedan does better on 87, my s/c gp...the higher the better.

Marketplace, a consumer advocacy program in Canada tested this; proved on the average sedan would not benefit from premium.

 

Since my experiment is w/ alky-free premium, I assumed that was why the mpg improved. Most of the driving was city driving. I'm currently re-running the experiment to see if cold weather driving has any effect.