Gas Type for 95 Chevy Silverado (1500/V8)

[userpete1037]

I currently use 93 octane in my truck. Is it okay to drop down to 89 or should i keep using 93? My work truck is a 98 w/vortec engine and they only allow us to use 87.

[2000CAYukon]

Originally Posted by userpete1037

I currently use 93 octane in my truck. Is it okay to drop down to 89 or should i keep using 93? My work truck is a 98 w/vortec engine and they only allow us to use 87.

If your 95 is stock, then it was designed for 87. You will not get any benefit from a higher octane without reprogramming (reflashing the chip or buying a new one).

If you get pinging on 87 octane, then it could mean that the timing is off, someone replaced the chip or you have some engine issues.

//2000CAYukon

[samthecarman]

i have a 97 silverado w/5.7 and when gas prices were lower, used 93, but went down to 89 to save money. no problems. like the previous post said it was designed to operate on 89 octane, you should have no problems except for occasional pinging under heavy load or full throttle due to the lower octane.

[userpete1037]

Thanks for you all's quick response....

[2500HD4x4]

You should be fine with 87. I live in Colorado now, which means that our grades are 85, 87, 91. Having been from elsewhere, I always ran 87. However, as someone else mentioned, high gas prices caused me to rethink. I've been running 85 against my will, but it does okay unless accelerating hard, driving in the mountains, or towing (in which case I'll fill up on 87 if I foresee the higher engine loads).

Just for kicks, I've seen 83.5 octane in rural Montana.