05Red5.3

got an 05 5.3 truck do i need premium gas? about to go fill up and was thinking to my self it might be a waist of money to put premium in here so figured id ask the truck guys!

brodystruck

iTrader: (6)

It's not necessary...

nightrunner

iTrader: (4)

not necessary but some claim better mpg with 93 compared to 87

05Red5.3

k, thanks. my LS1 ran like **** with 87 in it. lol. So i figured id ask.

Wide Open

The LS1 has much higher compression than the 5.3 so the ECM had to pull timing when you were running 87. I never saw any performance or mileage adavantage to using 93 compared to 87 in my 5.3 in normal driving. I did notice less pinging with the higher octane fuel when I was towing but no performance or mileage difference.

bgray

iTrader: (2)

do you guys ahve 94 in USA?

trever1t

iTrader: (14)

Only 91 in California and it is crappy assed gas at that. If you're going to "tune" go ahead and run and tune for the highest octane available. On a stock truck it's a waste of $ to run higher oct.

Wide Open

Yes but I think Sunoco is the only chain that sells 94. Most of the stations around here only sell up to 93.

blockheadnic

May sound like b/s but my truck usely gets about 340 out of a tank of 87, but one week i took it to the track on a fuel tank of 93 made 6 pass down and ended up get 430 out of that tank all city miles.

Performance wise didnt notice anything but help MPG.

GTOsRamairSilverado

some of them only go up to 91. for example Valero