Truck dosent like towing

[Southern Pride]

What's the ratio for 60 mph? Cuz maybe I'm doing 60 @ 1500 or so I know it's definitely under 2000 rpms and I'm def going above 50-55mph

My damn speedometer is still off but thanks to the smart phone I downloaded a dyno app that gives me a speedometer so when the speedo says 50 I'm really doing exactly 40

 

[rico47635]

What's the ratio for 60 mph? Cuz maybe I'm doing 60 @ 1500 or so I know it's definitely under 2000 rpms and I'm def going above 50-55mph

My damn speedometer is still off but thanks to the smart phone I downloaded a dyno app that gives me a speedometer so when the speedo says 50 I'm really doing exactly 40

1740 RPMs


Here is a link to the calculator. Remember that whatever size your tires are need to be cut in half for the part that asks for the radius. I made the mistake of entering the diameter the first couple of times I went to this site and got some really off the wall results. LOL!

http://wahiduddin.net/calc/calc_speed_rpm.htm

 

[Hezsus]

according to that calcuator i run 1200 rpm at 60mph

Also i guess the trailer i was towing is 1100 kgs not lbs.. more like 2500lbs which would help explain a little bit too.

the smaller tires helped a bit but the stock computer made it worse.

My conclusion is to forget about using overdrive while towing.. since its probably better on the trans and all as well.

My speedo also reads fast.. something i keep forgetting about (probably saved me a few tickets tho lol)

 

[MOBS]

I didn't even tow @1200rpm with the stock setup I had, so your engine is really running inefficiently, so you pretty much have 2 choices here: 1) regear(tires/gears); 2) lower your cam duration....but yeah, it's not good on the trans atall to tow more than vehicle weight in OD.

 

[Hezsus]

thats just according to the calcuator, i'm pretty sure i'm still up around 1500 rpm, my trans in this truck has also been rebuilt, and i'm not sure whats been done to it. also, just took off with our heavy trailer in 4lo and it took off beautifullyso i'm thinking it just a tire/gearing problem.

 

[MOBS]

Yeah, but just imagine what your gearing would have to be to match what you get in Lo.

 

[Hezsus]

Haha yeah, I wouldnt expect what i got in low out of even 5.46(not sure if that right) gears

 

[Southern Pride]

Hezsus **** man no wonder you're truck is ******' out towing if you only run it in OD. Listen:

0-45/50 NO OD
50+ OD especially on a highway or interstate that is flat...OD is only for after you have a ton of momentum. Any time you want to get going make sure that ***** is out of OD you'll notice a night day difference...On vortecs to take it out of OD don't you just put it in 3 just like mine?

 

[rico47635]

I thought Chevy changed the design of the transmissions when they came out with the Vortec engines so that all you needed to do was push a button to go from OD to D. Maybe that was on Fords where you could do that.

 

[Hezsus]

Yeah i usually cant get it into overdrive unless i'm cruising on flat ground.. even then sometimes it downshifts. but when i do keep it in od the mileage sucks, today i towed with it in 3rd (which is 4th too?) and my mileage sat right around 8mpg 2000 rpms and it diddnt bog down.. i guess i just cant use overdrive with anything on behind.