gas mph 05 vs 08

[Pure_Justice]

With regards to increasing the octane level on the H2, I agree you will always get a better ride uping the octane. But that is with any vehicle, whether its a H2 or a Ford Escort. With respect to recommended octane, it is what the manufacturer specifies as an octane that will not damage the engine over the life of the vehicle.

I also will pull out the owners manual and double check my eyesight.

Interesting topic of discussion, maybe I will have to experiment with high octane as well.

[Pure_Justice]

I stand corrected. According the the owners manual, 91 is what is recommended, but it does say that you can use 87 octane. Which is different then what the Service manual says, which just specifies 87 octane.

Very interesting.

[HummerJim]

I pulled the owners manual out too, and 91 octane is "the recommended fuel" for the '08 H2. I've run regular twice and noted that it downshifts more on hills and doesn't idle as smoothly.

[mikejr]

Originally Posted by HummerJim

I pulled the owners manual out too, and 91 octane is "the recommended fuel" for the '08 H2. I've run regular twice and noted that it downshifts more on hills and doesn't idle as smoothly.

Now that you say that, mine doesnt have a rough idle anymore now that I use 91 fuel. It idled like a high lift cam was in it when I used regular fuel.

[lasvegash2]

same here...rough idle and hesitation under wot...with 91 no problems...my escalade is the same way premium only but it states it on the gas filler where in the h2 it doesnt say anything...why is it the escalade is 403 hp and the h2 is 393 hp...what did they do different..intake or exhaust?...i know its only 10 hp but just wondering if someone knew...

[TGCOFTN]

I have a 2007 & 2008 H2.......and to be honest, I am not impressed with the 08's fuel economy at all. I could be wrong, but I dont think something is right on my engine on the 08, it seems so WEAK to have 393hp. I can take the 07 and go up hills without downshifting, and the 08 has to downshift on pretty much every hill when it has more horse and more torque. When I first got my 08, I did hit 19 mpg with it one time, but now, I cant seem to get it over 14mpg. I am gonna take it to the dealer and let them check it out. I really dont see any differences between the 6.0 and 6.2 in fuel economy cause with my 6.0 I have gotten as much as 18mpg with it.
Most will say its impossible, but as long as you keep it around 55---57mph on the interstate with the cruise on, it will do it.

[Stainless]

I am usually easy on the pedal and only getting about 12.2 avg!

[mikejr]

Originally Posted by TGCOFTN

I have a 2007 & 2008 H2.......and to be honest, I am not impressed with the 08's fuel economy at all. I could be wrong, but I dont think something is right on my engine on the 08, it seems so WEAK to have 393hp. I can take the 07 and go up hills without downshifting, and the 08 has to downshift on pretty much every hill when it has more horse and more torque. When I first got my 08, I did hit 19 mpg with it one time, but now, I cant seem to get it over 14mpg. I am gonna take it to the dealer and let them check it out. I really dont see any differences between the 6.0 and 6.2 in fuel economy cause with my 6.0 I have gotten as much as 18mpg with it.
Most will say its impossible, but as long as you keep it around 55---57mph on the interstate with the cruise on, it will do it.

Dont forget since the 08 has the 6 speed transmission it is going to shift more than the 07 that doesnt have the 6 speed tranny.