interstate speed/temp/boost?

GHeTTo JOe · #1 (**permalink**) 07-02-2009, 11:25 PM

went on a trip on I-35 going about 75MPH running about 2400 RPM boosting anywhere from about 4 to 9 psi staying at about 6-7 most the trip is this common? also my tranny temp was steady at 210 degree F, normal? i got 12.7 mpg on the 225 mile round trip had a four wheeler in the bed on the way back. was fighting a side wind of 20-30 mph outside temp of about 80. 1994 f250 stock turbo idi LT265/75R16 tires auto 4x4 supercab crew of 4 stock intake exhaust except muffler delete. whats anyones thoughts on these readings normal? thanks for any input!

fonefiddy · #2 (**permalink**) 07-03-2009, 05:49 AM

Everything seems about the same as My 93. Except I get a little better fuel mileage. Around 16-17 MPG.
The 210 tranny temp seems about 10-20 high. Same as the coolant temp? Might want to get a big external tranny cooler?

GHeTTo JOe · #3 (**permalink**) 07-03-2009, 06:51 PM

that sounds right for not pulling a loaded trailer? coolant temp was below half on normal but cant really trust it needle does not move very smoothly

David85 · #4 (**permalink**) 07-04-2009, 01:34 AM

MPGs are a little on the low side, and trans temp could also be better.

210 is not dangerous, but considering the truck was essentially empty, that is kinda high. Where is your sensor?

Driving my truck like I stole it, I measured 180F peak at the valve body sensor.

I wonder if your torque converter is locking. I also wonder what gearing you have to run RPMs that high with an E4OD transmission.

Festus Hagen · #5 (**permalink**) 07-04-2009, 01:47 AM

Without knowing the OD ratio, I'd say 4.10!

Just did a quick calc. 3.958 = (2400*31.6)/(336.13552*.76)/75
R-gear = (rpm*tiredia)/(336.13552*T-ratio)/MPH

-Enjoy
fh : )_~

mistakenID · #6 (**permalink**) 07-04-2009, 05:49 AM

The tire height may be the cause of the somewhat lower mpg. Taller tire without correction is going to show less mileage on the odometer.

JesterPgh · #7 (**permalink**) 07-04-2009, 10:44 AM

If the stock tire was originally a 235-85/16, believe it or not, the 265-75/16 is almost identical in "height", and actually, slightly shorter; the first (235-85) converting to 31.7, the second (267-75) converting to 31.6

Dave Sponaugle · #8 (**permalink**) 07-04-2009, 12:32 PM

With 31" tires a 4.10 gear and an E4OD would cruise at 2400 at 76 MPH.

Wider tires = more wind resistance and more rolling resistance.
More resistance = lower MPG numbers.