So I figuredout my gear ratio, tire size, speed = rpm today. With my 4.10 gears I'm turning 3162 at 70. I know the mac rom of these engines its like 3600, so is it safe to make extended highway runs at these rpms? I'm kinda afraid my crank is going to exit stage oil pan if I do. any input would be appreciated.

Nothing new. I wouldn't worry about anything other than fuel economy.

Wow I meant max rpm. My phone is stupid and won't let me edit the post lol.

what doyou think my economy should be? In town vs highway? I haven't figured it out yet but alot ballpark would be cool.

id say around 18 mpg on the highway and city depends on if you drive like me(show off at every stop light and blow smoke and blast through the gears) or drive like my mom( ease into the throttle so lightly the IP is like WTF man move the throttle already).

really? 18 mpg with with a three speed and 4.10 gears? Lol I love diesel.

and I drive like your mom at the moment. My exhaust is broken right under the cab and I'd go deaf and or get pulled over if I didn't.

18 tops i guess. other people with the same set up get a max of 18 on the highway.

I'm happy with that. That's at least six better than my old ford straight six gasser lol.

I know your pain, with trying to use your phone here. I try to stick to my laptop, but if I have a patient I have to transport to the medical university 100 miles away, my phone is all I have to get here. What, I mean a STABLE patient. Don't judge me. If you do use your phone, I'd turn off the predictive text. On mine, ten pharaoh likes to scramble all the wonderbread so bad that yen have no ideal what I'm trying to wrigley field.

I know your pain, with trying to use your phone here. I try to stick to my laptop, but if I have a patient I have to transport to the medical university 100 miles away, my phone is all I have to get here. What, I mean a STABLE patient. Don't judge me. If you do use your phone, I'd turn off the predictive text. On mine, ten pharaoh likes to scramble all the wonderbread so bad that yen have no ideal what I'm trying to wrigley field.

but the plastic p_o_s is so smart.....

where do i buy a dumb phone?????

my truck in overdrive runs around 2,500 rpm at 70mph and i got 21 to 22mpg last weekend, now my tranny is junk and looses overdrive randomly and when that does im running 3,000rpm at 70mph and i notice a huge drop in mileage, never ran it long enough without overdrive but i would guess im getting around 15 to 17mpg. dont quote me on it as ive only ran maybe 200 miles without overdrive at one time

i am not sure about yours..but in a motorhome with 456 gears..it runs 3200 at 65..at 75mph i dont even look..ha ha ha ha ...and i have done it all day long for several years the engine loves it..:)

http://www.youtube.com/watch?v=LfIbFi2MLkU

I know your pain, with trying to use your phone here. I try to stick to my laptop, but if I have a patient I have to transport to the medical university 100 miles away, my phone is all I have to get here. What, I mean a STABLE patient. Don't judge me. If you do use your phone, I'd turn off the predictive text. On mine, ten pharaoh likes to scramble all the wonderbread so bad that yen have no ideal what I'm trying to wrigley field.

Yeah unfortunately the cord for my laptop took a shit and I'm broke till idk thanks to this damn truck lol

And holy shit whiskey.after hearing that I don't feel so bad for my engine at 70 lol.

I`m in the same boat as you. 4.10 th400. With 3 years of keeping gas receipts and knowing my mileage I get about 17-18 mpg. Ì run at 60-65 mph most of the time. I sometimes drive 75mph and have buried the needle on a few occasions 85mph+. With gas trucks that I`ve had, all TBI, burying the needle meant having way less gas than before. Not with this truck. That said I once made a trip where I drove 200km`s(120mi) round trip at 80kmh/55mph and struggled to put in 20L/ 5.5 g. So you won't get legendary fuel economy at those RPMs but it's still decent.

Thanks for all the input guys.