Gear ratio over drive or direct for heavy haul up to 110K?

I will say that I care about fuel economy, I would love to see six. I just don’t place it at the top. My truck is 12 years old and pushing 800,000 miles. That’s 12 years and 800,000 miles of oversized freight. Will your new truck with new specs last that long? IDK, but it’s a question to ponder

 

When I ran a six axle I got close to 6 with a mechanical cat. With 3.90 rears. I get 4.5 with the current setup. If you are doing 4 there is more going on

 

RPM’s to high at cruising speed is down the list of importance, way down. You’ll have a truck that’ll cruise fine on flat ground but we’ll see how it does pulling 5% with 120,000+ or more importantly how it lifts off in soft ground with that much weight.

 

I’m with ya, I’ve been told to let her pull way down and pull. For me it seems like it pulls better revved up.

 

I don’t know about Detroit, but Cummins even recommends higher rpm for pulling higher weights. Trucks and truck engines haven’t really changed. They claim lower rpm because they are running 5 to 600hp and 2050 ftlbs to pull >80k. Once you get to any real weight they recommend doing things the old way. People leave that part out.

 

Couple inches of soft mud on a slight incline. PING!!! Goodbye driveshaft!