older cat vs. newer paccar engines

Could gearing be part of the issue?

 

Comparing a CAT to a MX is Blasphemy !!

 

Auto shift trans literally had no bearing on the power.

It is an automated manual transmission without a Torque Converter.

Real Automatic transmissions like an allison have a Torque Converter which has fluid coupling losses when unlocked.

The CAT you drove most likely was a higher TQ rating.

I'd rather have more TQ to get the job done in a Truck...HP games are for cars without much weight.

 

38 39 on the boost is what my old 455 paccar did in 2015 model ... I’m not sure if your truck is new but if it is wait till 60,000 miles when they do the first valve adjustment then you’ll have a idea of it’s true power.. they neuter it in the ecm till around that point

 

Went In Birchwood foods shop at kenosha wis yesterday and saw a t660 with the hood open ...mx 13 ....looked like a plumbers nightmare !

 

First off, the driver and his habits control the fuel economy more than the engine it self. Also the newer engines are deceptive being there power is all on the lower end , vs the older engine rev higher to pull. Also without seeing how the engine is programed its hard to say which power level it programed at, the option menu in programing has a lot to do with the performance of engine.

They two engine just have a different feel as far as the pulling and performance.

The tractor I have been driving as of late, Are shared totally, I rarely get the same tractor twice during the same week, but I consistently stay at or close to 10 mph. Now admittedly USPS loads are really light, but there's also other things like keep your jake off except when going down hill, do not use it as a brake in traffic, slow down early keep a large following distance, this keep you from the slow down speed up game, there's a ton of stuff that have a affect on your mileage, tire pressure, how you climb hills, it all matters not just the engine size. Even understanding the power curve of the engine can have a large impact on your mileage.

I actually find the newer generation engines have more pulling power for the displacement size over the older engines. put a C13 cat against the MX13 paccar and the 13 liter cat will be left in the dust cloud. The though of comparing a 15 or 16 liter engine to a 13 liter, off course the newer 13 liter does not perform like a older larger motor. But it will go further on a gallon of fuel.

 

What rpm do you run at going up the hill?

 

From you post i deduct you run too high rpm's.
1500 rpm is when then torque curve goes down.
PACCAR Engines
The are low rpm engines.
Don't be scared to run lower rpm's,they were build for it,unlike older engines.