ECU

Hey everyone, sorry if this question has been answered before. I'm not good with forums lol. I am looking at possibly buying my first truck. I have always worked for other companies so I was wondering if when you buy a new truck if it automatically comes with a speed limiter? I am looking at a 2025 Peterbilt 567 day cab. My current company has the speed set at 63mph and in NH the speed limit is 70mph. If it comes from the factory with a speed limiter does anyone know what that speed is? Also can it be removed in the ECU if I own the truck?

 

I keep reading that there is a factory set speed limiter but it won't say what speed. It does however say 2000 - 2100 rpm's. Is anyone familiar with this truck who might know what that equates to in speed. I'm guessing gears have a lot to do with it as well. I can't find anywhere the gear options for that truck.

 

So if anyone could help me if said vehicle was a 2025 Peterbilt 567 day cab 605/2050 cummins with Eaton Fuller 18 speed automatic with 4.10 gears what would the top speed be at say 2000 rpm's? Thanks in advance

 

So I found a calculator online but I'm not sure if I filled it out correctly? So with 4.10 gears, 42" tires (11R 22.5), RPM's at 2100, transmission gear ratio at .73 it says that I would be at 87.7 mph. Does this sound right or did I screw it all up lol? I really was hoping for the 4.10's because the interstate is really up and down and our current trucks are at 31mph going up long hills. I also don't want to be at 2000 rpm's maxing the truck out at only 70 mph. So I may have to go to like 3.90 gears.

 

That's weird because everything I research says higher gears for hills. I know don't believe everything you read lol. I still have to believe that a cummins 605/2050 with 4.10 gears is going to do better than 31mph up hill though. Maybe I'm crazy

 

Just for the record I am referring to a 5500 gallon septic truck. Tandem with a 20k steerable drop.