Question About Tractor

I’m driving a 2020 Freightliner Cascadia with Detroit Engine and 10 speed Eaton transmission. I can’t seem to make this tractor pull hills right when loaded. It came with progressive shifting which I immediately had turned off. If I let this thing drop below 1400 rpms when pulling it falls flat on its face. The power band seems to come in at 1350 and stays till 1750ish.

Took to shop and talk to mechanic and he showed me that most torque is seen at 1050 rpm so took tractor back out empty and let it lug down on hill to 1050 and floored the fuel to it and it fell flat on its face again. He explained to me that the newer tractors don’t run like the older ones where you have to stay in them. So what am I doing wrong? Tips? Advice? Anything? Thanks!

Brian, that's life in a governed truck. We all experience it. These governed trucks simply can't get enough fuel when climbing a mountain, so... going 25 mph uphill is something you just have to get accustomed to.

You aren't doing anything wrong.

I'm in a 2016 Peterbilt with an MX13. Best torque is around 1150. At 1050 it'll fall on its face going up a hill. Best horsepower is up around 1550 to 1650 which is where it pulls hills the best. At 1100 rpm I'm down shifting.

Torque will get ya going but horsepower keeps ya going.

Torque and horsepower curves are similar between the paccar and Detroit. Although, the Detroit likes the higher RPMs.

Brian, that's life in a governed truck. We all experience it. These governed trucks simply can't get enough fuel when climbing a mountain, so... going 25 mph uphill is something you just have to get accustomed to.

You aren't doing anything wrong.

Old School, thanks! While at the shop, we turned the speed up to 75 but I asked to adjust the torque and horsepower up also which they said they couldn’t till they talked to Freightliner. Our tractors are leased from Ryder so they are supposed to come down this week and meet with us to see if many some other adjustments can be made either with the torques, horsepower, and even something with the turbo.

25 up a hill? 10 speed autoshift sounds about right. That is from my limited experience.

10 speed manual, I'm flying up at 31!

Brian, that's life in a governed truck. We all experience it. These governed trucks simply can't get enough fuel when climbing a mountain, so... going 25 mph uphill is something you just have to get accustomed to.

You aren't doing anything wrong.

One thing so many fail to address is the rear end gears. Many companies spec their trucks for fuel economy and will go with a rear end gear that will cruise down the highway at a nice low rpm with the engine putting forth little effort. The trade off is the truck falling on its face when it hits a hill but there's really no way around it and you just deal with the fact that you'll be crawling all the way to the top.

Also forgot to mention that the running gears are 3.25.:1. If this had had a 13 speed manual instead of the 10 speed manual and 3.70:1 or higher would make a difference also. Thanks everyone! I thought it was something I was not doing.

You'll be hard pressed to find anyone using 3.70 rears anymore that isn't doing heavy haul or some sort of dump, log or regional work where you're constantly in the hills. They're much too concerned with fuel costs and with your particular setup, it's definitely gonna be a dog on the hills.

The lowest my 2019 has ever gone is 8th and 26 mph. It's what they are designed to do for the fuel economy. So as much as I don't like it, I have come to accept it. We would all like to be not loosing momentum going up the hills, it's what it is. When I drove tankers, I had a 379 Pete 10 sp Eaton, it would climb most of the hills in 7th and 35-37 mph. I was always .axed out in all 5 compartments. Mine was an unusual tanker. 51' with 5 compartments. Most are 48' and 4 compartments. At 80,000 lbs. She did ok.

I asked of they could do something on this tractor and said not without sacrificing fuel economy, which Swift will not do. And I don't blame them with the amount of tractors that we have.

Raptor

You'll be hard pressed to find anyone using 3.70 rears anymore that isn't doing heavy haul or some sort of dump, log or regional work where you're constantly in the hills. They're much too concerned with fuel costs and with your particular setup, it's definitely gonna be a dog on the hills.

We run basically the mountains here in southwest Virginia. We do have 2 other tractors that are running the 3.70 gears. Here is what stumps me and that is we have 2 other Freightliners with the Detroit engines with 10 speed trannys but 3.08 gears and they pull circles around my truck. Makes no sense to me but who I am? LOL Thanks again for the wisdom and insight!