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Interceptor SUV Tire Pressures?

Started by MiWiAu, January 09, 2017, 12:54:12 PM

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MiWiAu

Curious if anyone has an Interceptor SUV or access to the placard information.

I was wondering what Ford recommends for tire pressure on the PI SUV vehicles, but the manual just says to look at the b-pillar placard. I can't seem to find a good source of this information online.
2013 XSport

MiWiAu

Nevermind. I found this on a salvage website for a PI SUV. Looks like 36/36 for anyone who is curious.
2013 XSport

derfdog15

Good find, may I ask why you needed this info?
2015 Tuxedo Black SHO PP -(SAE corrected): 369.4/451.4 - Gone to the automotive graveyard but not forgotten

2016 F150 FX4 Sport - 3.5L V6 Ecoboost - Stock for now

2003 Redfire V6 Mustang - Building to be an 11 second car

MiWiAu

#3
Quote from: derfdog15 on January 09, 2017, 01:16:50 PM
Good find, may I ask why you needed this info?

Because I'm way too analytical. LOL. You might be sorry you asked, but here you go :) :

I was just curious if Ford recommended a higher pressure for PI vehicles to increase overall carcass stiffness for a more performance oriented application (where ride comfort might not be as big of a concern as it is on civilian models).

I believe, though, that the PI SUV recommended tire pressure (36/36) is higher due to the lower internal volume of the PI recommended tire (245/55R18).

I did a very simplistic volume calculation of the Sport tires (255/50R20) vs PI tires (245/55R18), and my simple calculator says you'd need to run 36.8 PSI in the PI tires to have the same number of air molecules as my Sport. My calculator, though, is very basic and does not take into account any differences in the well design/volume of the wheel itself, which probably accounts for the difference I'm seeing between my 20" OE wheels and the 18" PI wheels.

Using the same calculator, my winter Blizzak tires (235/65R18) have a slight increase in volume over my Sport tires, and in theory, I could run approximately 31.7-32.5 PSI in the Blizzaks and have the same number of air molecules as my OE 20" tires. I'll just stick with my factory 35 PSI, since that's where the alignment was done on the winter setup.

The calculator would probably work decently well for different tire sizes on an identical rim.
2013 XSport

SHOdded

Or maybe they are just increasing fuel efficiency LOL.  Good info!
2007 Ford Edge SEL, Powerstop F/R Brake Kit, TXT LED 6000K Lo & Hi Beams, W16W LED Reverse Bulbs, 3BSpec 2.5w Map Lights, 5W Cree rear dome lights, 5W Cree cargo light, DTBL LED Taillights

If tuned:  Take note of the strategy code as you return to stock (including 3 bar MAP to 2 bar MAP) -> take car in & get it serviced -> check strategy code when you get car back -> have tuner update your tune if the strategy code has changed -> reload tune -> ENJOY!