Fuel Mileage Question

[AzDragonLord]

I run E85 fuel about 99% of the time in my 2009 Sierra. I make a lot of trips between Phoenix and Los Angeles and my MPGs typically run between 15-16. I check my mileage each tankful using the calculator-method.

 

I've tried a few things to see if I can get better mileage, like keeping my highway speed at 65 (vs 75) during one entire trip which kept the RPMs below 2000, but did not increase my mileage at all. I also installed cruise control which helps me, but did nothing for my MPGs. I did install a bed cover which gave me a whopping 1 MPG increase...not much but every bit counts. I'm not a lead-foot and I keep the (still factory) tires at the recommended 35 PSI.

 

I was really shocked to see that keeping my speed limited to 65 did nothing to help with mileage! Could the AFM system be hindering the typical MPG saving techniques?

[b00fa]

I run E85 fuel about 99% of the time in my 2009 Sierra. I make a lot of trips between Phoenix and Los Angeles and my MPGs typically run between 15-16. I check my mileage each tankful using the calculator-method.

 

I've tried a few things to see if I can get better mileage, like keeping my highway speed at 65 (vs 75) during one entire trip which kept the RPMs below 2000, but did not increase my mileage at all. I also installed cruise control which helps me, but did nothing for my MPGs. I did install a bed cover which gave me a whopping 1 MPG increase...not much but every bit counts. I'm not a lead-foot and I keep the (still factory) tires at the recommended 35 PSI.

 

I was really shocked to see that keeping my speed limited to 65 did nothing to help with mileage! Could the AFM system be hindering the typical MPG saving techniques?

 

switch back to regular fuel you will get about a 20% increase in mileage E85 is crap not worth the money

[tanked_darren]

I also installed cruise control

 

How did you do that? Is it OEM parts?

[AzDragonLord]

I also installed cruise control

 

How did you do that? Is it OEM parts?

 

 

No OEM, I found this aftermarket kit on ebay for $100. Took about 3 hours to install.

[AzDragonLord]

switch back to regular fuel you will get about a 20% increase in mileage E85 is crap not worth the money

 

I disagree there. I may get less MPG, but if I figure the cost-per-mile for each fuel type I usually come out ahead, and E85 is made domestically and burns way cleaner...worth the trade-off in my book.