89 octane is better for the 6.1???

[Jakez]

Originally Posted by topfuel67

I do A LOT of city driving. I make 10-15 stops each day and have maybe 20% highway driving. I always average high 14s to 15mpg (evic says 13s, but I always fill my tank and divide miles on my trip by gallons-its usually 250 miles to 16.5 gallons). I launch hard at every light. I floor it on every on ramp. I'm scared to pull fuse 11 because I don't want my car to forget the valuable lessons I've taught it (first one was goto 6000 rpm and make max power-on the dyno). I also run 89 octane and am convinced it is the right mix for a basically stock car. I have the airaid CAI and the suitcase delete. Unless you have programming the high octane isn't burning hot enough. I know tuning on old cars and my old V8s always reach 30+ degrees of timing above 4000 rpms. I've seen members report here that our cars only reach 18 degrees timing (or less) at WOT at max RPM on the dyno. Plus my car never bogs off the line like some people complain here. When I've ran 91 it doesn't have the same punch. With 89 it rips the tires so much easier.

Ok wtf..

[JP300c]

maybe he can't read his owners manual? not sure...i put nothing but premium in my srt...and it will ALWAYS stay that way...mine only bogs down when i let my foot off the pedal...heh

[stevesrt8]

Higher octane fuel burns SLOWER. There's no more horsepower, just more additives.

Seems to be about his preferences and his car. That Butt dyno thing is notoriously innaccurate, but an enthusiast owner can really tell what their car is doing. These PCM's pull timing like crazy all the time, so maybe we don't need higher octane with our pig rich programming.

I've not heard anyone else with that opinion, but his input is appreciated. I may try a tank of 89 and see if I can "feel" a difference.

I primarily use Shell 93, as it's one of the best "top tier" fuels out there. I have no issues, my car has very snappy responses and rips the tires loose at will.

[MADDOG`]

Mine doesn't like 89...tried it and it pinged under heavy to WOT. Went back to 91 and all is well. I have a CAI only.

[Camel XTC-R]

if you dont have detonation then yes you will make more power with lower grade gasoline, say you port polish the heads and lower the compretion sometimes with good weather you can use lower grade gasoline

[Camel XTC-R]

Originally Posted by Ultimatecarman45

The problem is that the computer will usually make it so that you don't know if you have detonation or not, so you won't know if you can run the 89 and get the power or if you need 91+ to make sure.

very true thats why i use 98oct all the time

[srt8danno]

I only use 93 and feel as if I would commit a mortal sin to use anything else. jmho

If you’re not careful the Octane Police will pull you over for using the wrong amount! (So Dubster told me once)