What does rear ratio in a semi means?

What do you consider a heavy load? Heavy haul or 45,000?

 

So if I'm running the PNW, maxing out at 45k, is an 18-speed with 3.55 overkill? I know my engine decal says it likes to run at 1800 rpm. I'm just wondering because she is an ABSOLUTE COW on those hills.

 

What engine do you have? Have you looked up the torque and HP curves online? 1800 is pretty high unless you’re running an old mechanical engine.

 

I have a 2008 Series 60, 14L with 515hp.

 

At 1800 you’re on the downhill side of your torque.

 

I can't read Chinese! So what should be my cruising rpm? I'll have her set at about 71 mph and the rpm stay at around 1600. What does the 1800 rpm mean on the engine label then? Max rpm? So looking at the graph, I achieve max torque at 1500 rpm?

 

Your engine makes maximum HP at 1800rpm. But horsepower doesn’t get you up the hill, torque does. Your engine makes peak torque between 1200 and 1500rpm.

 

Sure it does.

Horsepower is what enables a truck to maintain a speed.
Torque is what enables a truck to accelerate to a speed.

Give me the horsepower, everyday.

 

Yep. The red truck in my avatar has tall 24.5 and 4.42s. it's 1600 at 65. The other truck with 3.91 and LP 22.5 is 1600 at 65 in 12th (.73) and 1400 in the last split with the tall .62 od

 

I'm new to the forum and I'm trying to figure out why my truck requires 11r22.5 tires on the steers and 455/50r22.5 on the drives which is a super single. But here is the catch. I took the super singles off and put duals which is 295r75 22.5's. I have 3.90 rears and it shows that it is the closes tire to the super single. Is it alright to run the 11 r 22.5 on the front and the 295/75 r 22.5 on the drives. It just seems weird to me.