Gear Ratio Question

They're both fuel injected big blocks that make most of their torque around 1200 -1400 rpm.

 

The fuel economy drop off isn’t as severe above 1500 on an older electronic Cat compared to an Acert.

 

I know Bully Dog makes a tuner for that engine, I’m not sure if there are others or not.

 

Why is that?

 

Technically, I can’t answer that. All I can say is from personal experience. The company I worked for ordered all their T800’s the same. The 2005’s were the first Acert’s he got. He send us driver that we’re getting them up to Cat in Missoula to have a meeting with their manager. We were told to run them between 11 and 1500 for the best economy. Well they were ordered with 3.70 rears like all the other trucks. And that meant we were running 62 or so, which wasn’t that big of a deal given where we were running and the weight we pulled. If you ever did have to run 70mph or so to get somewhere fuel economy suffered. When he got the 07’s and 09’s they came with 3.55 rears and their fuel economy was better at 65+ because their rpms stayed 1500 and lower. Then in 2011 when he started building gliders with older Cats he went back to 3.70 rears like before.

 

My brother has one for his ISX and he likes it. All he said was downloading the tune onto the tuner was a little bit of a headache. But he’s also not very tech savvy.

 

He deleted the emissions and did the Full Tilt intake manifold and some other things at the same time. So he wouldn’t really be able to say how much was only from the tuner.