Originally Posted by
TexasGuy001
Sorry, but I don't own a newer Expy either. I was just wondering about octane and thought I would respond here. I have a 95 F150 with a 5.0 and if I run 87 in it, it will ping on the highway when running the AC. I run 89 in it. All 3 F150s (85 351, 95 4.9, 95 5.0) I have had did this as well as an 89 Mustang. All of these vehicles were run on 89 instead of 87, to eliminiate the pinging.
As stated before, you could adjust the timing, and then the vehicle would run on 87. No harm done, except for 10 cents more per gallon.