truck had 48000 miles when i first got it. i changed the coolant around 55. it didnt look in too bad of shape but i wasnt sure if it had been done before and it was getting around time to do it anyway. no special coolant was used. just the wal-mart brand super tech 50/50.

 

Yeah, but 87 octane burns quicker than 93, and without advancing your timing, you won't get as much power out of 93. Run it in the 1/4, and you'll have quicker times with 87. I know, because I've done it several times.

 

I just set an all time high gas mileage record for me of 16.15MPG running 75 - 80 MPH. It is up from 14.4 on the same trip, thanks to my gutted cats.

 

Edit: Re-posted question in other thread.