[Jackpine]

Originally Posted by double j

also do you know about the octane rating is it going to make a big difference

Double j, I'm going to say this: Our trucks were designed to run on 87 octane fuel. As I'm sure you know, octane rating is just an indication of the fuel's "anti-knock" properties - nothing more. A higher octane fuel is more resistant to being ignited under pressure and, when it does ignite, it tends to burn more slowly. That's all there is to it.

With higher octane fuel, in our engines, we can advance the spark a bit to ignite the fuel charge earlier, since it needs the earlier ignition to complete the burn "on time". The overall effect is a more "controlled push" on the piston in the power stroke. Some people claim this give them enough of a power boost that their mileage improves enough to justify running the expensive stuff. That may well be, but you would have to check that yourself. You WILL experience more power due to the more "controlled" burn.

To really take advantage of high octane though, you need to be able to increase the engine's compression. This would involve an engine rebuild.

So, is there a BIG difference? Not enough for me to worry about filling with high octane gas. I think my truck has plenty of power. I can pass just about anyone traveling slower than me in a safe distance, even pulling a trailer. You, of course, could see it differently. You'd have to try both kinds of gas with custom tunes for each to find out.

- Jack