Looking at a couple of new trucks, either a F-150 6.2 or Sierra 6.2. I can pick up a new 6.2 Sierra for under 30K w/ Leather which seems like a no brainer. My issue is we're only alloted 87 oct. on our fuel cards. Any issues running these engines on 87? I'd go the 5.3 route but I'm about done with my current 5.3, while it gets good fuel economy it seems every other truck on the market has more power and more passing power and more trailering power on the weekends. I'm also replacing back brakes every 30 to 35K miles as they seem to just clog up with mud.

 

they will run fine with 87, plenty of people are tuned for 87 and making over 100hp more to the ground over a 5.3 stock.

 

Mine's still brand new (1,140 mi) so I haven't tried this yet, but GM says regular fuel is OK and premium or E85 are recommended. I think it would be safe to run the regular and just fill up with premium for weekend towing (plan ahead). Of course, you run the danger of getting addicted to the extra grunt when it's got the octane in the tank and you might end up filling up more often out of your own pocket.

I used to do this with a tuned 454 Suburban with no problems, and it had no ability to adjust itself to the different fuel other than sensing knock and retarding timing.

(This MIGHT be worth 2 cents.)

 

87 Is fine 93 is for optimum performance.

 

tune it for 87 and be done with it

 

As the others have said, 87 runs fine in the factory setup. The truck will pull timing to prevent knock, which iirc reduces the power rating to 385hp. That's still 60hp up on the 5.3, not to mention the added torque of the larger engine. Also as said before, if it's still not where you want it, you can have it retuned for 87 and it will lose no power on the cheap stuff and may even gain power over stock. Bear in mind that if you do not retune for 87 you will likely lose a few mpgs when you run 87 vs 91+.

 

Ther is a 10hp advantage with a93 oct tune compared to 87 oct

I started with 87 and went back And got a 93 tune

It was only 10hp but the truck runs way better with good gas

 

Wish i had a 6.2 so i could offer up some wisdom but allass i do not..

 

Swap that LT5+trans for an L92 and a blower

 

I think i have it sold already..