Need Help With New Truck

[montecarloman90]

im looking to get a new truck soon. its been a hard decision between the chevy and gmc. I think im going to go with the gmc. Now the hard part is which motor. I understand that you can now get the 6.2 but i have read in some places that you need to run premium gas. But on gmc website it says unleaded and that they are flex fuel engines. Does anyone no if u can run 87 in the new 6.2? Also does anyone no what kinda of mpg these engines get compared to the 5.3

 

thanks for your help

[fbachman]

im looking to get a new truck soon. its been a hard decision between the chevy and gmc. I think im going to go with the gmc. Now the hard part is which motor. I understand that you can now get the 6.2 but i have read in some places that you need to run premium gas. But on gmc website it says unleaded and that they are flex fuel engines. Does anyone no if u can run 87 in the new 6.2? Also does anyone no what kinda of mpg these engines get compared to the 5.3

 

thanks for your help

 

It is my understanding that all trucks can run on 87. I am not sure, but, in any case, i think running 87 should be ok.

 

I have a 5.3 EC GMC and I average 14.5mpg around town and up to 19 mpg highway. I would have to think that the 6.2 would be about 10%-15% less on both... but again, not sure.

[D&SYukonDenali]

6.2 recommends 92 octane or higher. Anything under, from what the dealer has told be, will result in engine "ping" (I think was the term they used). I have never tested it and alway ran 93.

 

With the 6.2 and 6-speed, I get 18 mpg (60% hwy, 40% city).

 

EDIT: That is in the YD, not Sierra though.