The f350 recommended rear tire inflation is 80psi. My view it’s to much for an empty truck. I set it at 60 and the TPMS don’t like it.
wondef if forscan can change that?
what is the min pressure before TPMS complains?

 

For me, it was 12 or 15 PSI (forget exactly) below pressure on sticker.
Yes, FORSCAN can change this (search on TPMS in FORSCAN thread).


I re-set lower limits to front 50, rear to 60.
I typically run 60-65 front and 70-75 rear towing, so I set my limits based more around that.
Not towing, I'm about 53 front, 63 rear.

 

Pre-Forscan change from 60/80 to 40/40 F/R, I could run 50 psi front and 65 rear without throwing the TPMS light. If the light came on, the pressure had to get damn close to OEM setting to shut off. Then I could back down again.

 

On mine 70 Psi is workable before the monitor says that the pressure is too low on the rears, although, last winter the light still came on when the temps went down to -30 and the tire pressure went lower because of that...

 

I have a DRW and I lowered all 6 tires to 60psi within the first 500 miles and never made a change to anything. I've never had a TPMS alert.

 

These trucks are much heavier on the front than the rear when unloaded, so I keep my pressures the same all the way around. I like 55 PSI.

 

I agree. But the problem with setting it lower than that (in rear), say 45 even, is that while towing, you won't get an alert until you are 25-30 PSI under your tow pressure,
(say 70-75, with high pin and/or tongue weight(s)).

So I run higher unloaded rear pressure, so I can keep my TPMS threshold at a higher level on rear, closer to my tow pressure.
I also think that lowering air pressure matters more on the front than rear, for ride quality, especially on CCLB, where rear tires are
a couple miles back there, somewhere

 

Q: Those of you who have lowered your tire pressure do you see a reduction in MPG?

Thanks….

Mike

 

No, not at all. It rides smoother unloaded also. I do not see any MPG reduction running 50 psi all around vs. Ford's 'recommended' pressure. Unloaded, 50-55 all around is still plenty of pressure.

 

Good to know I think I will lower mine a bit.

On my Fusion hybrid that gets an overall average 40mpg I see a noticeable difference in mileage if I lower the tire pressure even a few psi. Also if I raise to about 42psi from the recommended 35psi I get better mpg so I figured the truck would be similar.

Mike

 

The Fusion tires have a much softer sidewall so they are more effected by air pressure change but an E-rated tire has stiffer sidewalls. On a 6k lb truck my Goodyear Duratracs load range E, load index 125 look exactly the same with 50psi and 80psi.