Hey guys, This may sound odd, but I've found that I have plenty of power to hum along at 100-105 kmh in warm weather running 91 octane, but in cold weather it loses its zip. But it goes back to full power/ability in cold weather when I put in 89 octane. Don't know if that makes sense, but I've found that it works best for me to alter fuel based on the temperature here (to keep full power). Mine is EFI too. ~Josh
my dad used to blend fuels and formulated racing gas as well as what went from his refinery to the local gas stations.... keep in mind that the higher octane rating means basically that it burns slower. in a lower ambient air temurature the engine doesn't get as hot and you haven't got to worry about pre detonation. so the 87 octane will work just fine... when the motor is running hotter it will have a tendencie to "knock" or "ping" which are both symptoms of pre detonation. with my old street/race car with a high compression ratio if i turned back the timing a bit i COULD run on pump gas... but for max performance i would have to get the timing back to 32* total advance and mix 111 octane into the 87 at a ratio of 2;1 to get the high trap times at the track. the reason i used 87 octane to mix in with the race gas was that there are less detergents and additives in teh 87 octane and it's "cleaner" fuel albeit a lower octane. i used to also mix in tolulene because it changes the gravity of the fuel and works as an "octane booster" to keep it from pre dotonating.... sorry for the long post but i hope it helps.
Yeah that's kinda what I figured. If I were to run 87 or 89 in hot weather the truck idles and runs loud/rougher. But with the cold temperatures, the 89 seems to be the correct level for detonating right. 91 seemed sluggish at these temps (least with mine).
Milt is there anything you dont fn know???? thanks for your replies i learn something every time you post
Thank you Milt i thought i was crazy for a bit when gas prices dropped i tried premium and it ran like crap put in regular and was back to normal. I was thinking they switched at station maybe lol. I agree learn something new every time Milt touches the key board or get entertained. PS. when do we get to see these one legged space chickens?
I ran some Lucus thru my gas tank a week or 2 ago. When it got really cold it got like syrup. Kind of surprised me.
