Ratios... 3.58 vs. 3.75

[Tuckster]

Any significant MPG difference with a CAT 475 HP and auto tranny ?? Running expedite ?

 

[moose]

Any significant MPG difference with a CAT 475 HP and auto tranny ?? Running expedite ?

Big Difference if you drive over 66.mph
yet more info. is needed

for a St. truck ? , T.T ?
a 475 hp for a St. truck is way over-powered anyway , 1st thing to do is try to feed less horses .

what is the speed that you are running ?
how often do you 'Have" to run faster ?

where is your TAC at that speed right now ?
what is your fuel millage right now ?

tranny : have an O/D ? Direct ?
what is the tranny output ratio ?

wheels : rim size ?
low-pro ?

generally speaking , the lower the ratio , the lower the rpm at the same speed .



Moose.

 

[Tuckster]

I'm looking to buy a truck (TT) for OTR (Panther/Landstar/Schneider) and 2 of them I really like have autoshift ...both have the CAT 475. I'll probably run around 60 to 65 because of the cost of fuel. Sound like the 3.58 offers the better option.

 

[moose]

I'm looking to buy a truck (TT) for OTR (Panther/Landstar/Schneider) and 2 of them I really like have autoshift ...both have the CAT 475. I'll probably run around 60 to 65 because of the cost of fuel. Sound like the 3.58 offers the better option.

you will have to find out most's of the above questions before calling,
you can call ATBS of Denver ,C.O
they help truckers spec trucks for free,
good job on narrowing it to only 2 options . witch ever you chose , you will regret it later...
call an independent Cat dealer , and ask where the "sweet-spot" on this engine , then test drive the truck at 60 mph.
you want the TAC to be at the lower end of the 'sweet-spot'



Moose.

 

[piper1]

Unless it's got tall 11R24.5 tires on it, go with the lower ratio especially if it's an ACERT engine. Engine should turn 1300-1350 at cruise speed. 475 Cat is still a lot of engine even with a TT.

 

[Tuckster]

It has the 11R24's ..... What are the advantages/diadvantages of the taller tires ??

.... and the 475hp cat can be turned up to 550 3406 (but that won't happen).
I'm concerned about the fuel mileage and shouldn't need the hp for expedite.

 

[piper1]

There really aren't a lot of advantages to the tall tires. They can live longer since they turn slower but they stink for fuel economy purposes. There's a reason the big companies run low pro 22's!

Yea, definitely don't turn the hp up, 475 is lots. It costs a lot of money to be the first guy to the top of the hill!!!

Is it an ACERT engine? A 475 Cat built after Oct 02 but not an ACERT is what's called a bridge engine. Fuel mileage on a bridge is scary bad. Should say ACERT on the valve cover if it is.

 

[LDB]

Cat engines are bad on fuel compared to others from what I've seen and heard. If you have a C15/475 and an ISX/475 and a DD15/475 the Cat is going to get .5mpg less than the other two based on what I'm told. I had a KW W9 with ISX/450 in a 22' s/t and got 9mpg at ~62mph. In another 22' s/t with a Cat C9 engine I got 8mpg at 62. They were different trucks/gearing/tires etc. so they weren't that comparable however a huge ISX in a not aerodynamic at all truck getting 10% better mileage than a somewhat aerodynamic truck with a small Cat engine tells a little something. YMMV but no more Cat engines for me.

 

[Refer Hauler]

Agree 100% with what LDB say's. Me and a buddy run 3 identical International 9400I tractors all pulling reefers. Mine has a Detroit 430 Hp averages 6.42 mpg. His has a ISX 475 averages 6.67 mpg, He has a driver in the other with a CAT 475 twin turbo acert this truck will NOT get 6 MPG empty averages about 5.2 mpg at the best, I personnaly would not buy a truck with a CAT in it, too thirsty and expensive to repair.

 

[Broompilot]

A agree with everyone above Refer Hauler, LBD, and even the advice about ATBS.

But let me tell ya what they are also gona tell you. Your picture posted I believe a 379 Pete? Dual Exhaust thats .05 mpg lost, add in those trumpets lights and chrome air intakes and there goes a total of 1.5 mpg lost. Now add a CAT any Large Cat and there goes another .05.

I love what your driving looks great, but looks do not add $ to checking accounts.

Stay away from the old large trucks and the Over Powered Engines, ever see a truck not make it over the MTN? Me niether they always do maybee a little slower but 20 years ago 300 hp was the king of the kings, now we feel its under powered even with fuel at $4.50 a gallon.