I'm testing out some ways to increase my mpgs and I just brought my tires (Firestone Destination A/T's) up to 40psi. The max psi in that tire in 44psi. I got about 1.5 better overall mpg on only one tank of gas so far however my EVIC is constantly going off with high tire pressure warnings. Cold tire pressure is 40 psi. I re-trained the EVIC after I filled them up (also when they were cold) and the EVIC also read 40 psi. After an hour on the highway the warnings would start going off when the EVIC read 43 or more. Once one of those alarms go off you can't cancel it.

I'm still in the test mode about the tire pressure but is there way to change the alarm setting on the EVIC?

Also, Is 40 psi too much in terms of safety for this tire? 44 is the max psi (cold)
How do I determine if I'm putting too much pressure in the tire in terms of bad wear for the tire? I don't want the tire to balloon out in the middle and end up wearing out to much of the center tread and not enough on the corners.

I'm going on a 1,200 mile road trip in two days so I want to have this resolved before I go. Thanks!

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'04 Liberty Limited - 245/70/16 Firestone Destination AT's, Mopar tow hooks, Draw-Tite Class IV hitch, Skid Row Engine & Transmission Skids, Mopar T-Case & Gas Tank Skids, Extended Breather Tubes, Red Top Optima, Sylvania Silver Star head lights, Hella 500FF bumper mounted driving lights

The more PSI, the less tread contact with the pavement, which is why you get better mpg's, lower rolling resistance.

For normal driving conditions, it probably won't hurt anything. But when the roads are wet/slick or with covered in ice/snow, you'll probably want the extra traction.

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2012 Jeep Wrangler Rubicon

No, you cannot change the settings for the EVIC. FOR A REASON. There is a REASON there is a warning when your tires are overinflated.

HEY I HAVE AN IDEA! LET'S BYPASS THE SEATBELTS AND AIRBAGS AS SAFETY DEVICES!

HEY, GOOD PLAN. I HATE SAFETY!

Some people put lifts on their jeeps and we all know that increases the chance to roll and changes the bumper height, but (hopefully) they account for that when they drive. Other people add over 1,000 lbs in armor to their jeep and I’m sure their stopping distances are longer than stock, but (hopefully) they too adjust their driving for that. Some people pull large trailers, the list could go on and on. I’m just asking a simple question. “Can you change the psi setting on the EVIC” which was set up for the stock tires. I’m not even trying to disable the seat belt alarm. What about the people running an E rating tire with a max psi of 85?

The max psi for my tire is 44 psi (cold.) At 40 psi (cold) I doubt I am coming close to the max pressure for failure. My tire (firestone destination AT) is a size larger over stock (245/70/16) and therefore has a larger contact patch than the stock tire did (235/70/16.) So, logic would suggest that while a slightly over inflated 245 would have a reduced contact patch it’s probably similar to the contact patch of the stock 235. So unless you’re saying 40 psi is dangerous in and of itself because it might blow up I think it’ll be fine.

As a side note I have reduced the psi to 37 because the ride is a little less harsh than it was at 40.

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'04 Liberty Limited - 245/70/16 Firestone Destination AT's, Mopar tow hooks, Draw-Tite Class IV hitch, Skid Row Engine & Transmission Skids, Mopar T-Case & Gas Tank Skids, Extended Breather Tubes, Red Top Optima, Sylvania Silver Star head lights, Hella 500FF bumper mounted driving lights

You're right...but there is a REASON it goes off when the tires are overinflated. Because it's not safe.

Yes, people put lifts, big tires, 1,000 lb of armor, etc etc

You aren't going to blow up hardly any tire running 40psi, even if the max pressure is 35.

What about those of us with an E rating with a max psi of 85 psi? No such animal...but 80psi, yes. And most of us still run less than 40 psi. The idea of the TPMS system is to tell you when the tire has reached an unsafe pressure.

And is an increase of 1.5 mpg really worth wearing out your tires faster?

I would also like to know if the max tire pressure settings can be modified. I was running about 43-44 psi but dropped to 39-40 after adding the EVIC. There must be some help for those running E rated tires. I have always run tires at near the max pressure because they seem to wear more evenly, but I only have about a million miles to base that on.

Lewis
Lewis

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Mail Rated 2005 Red CRD Sport with large rectangular hole in top right behind the EVIC and above the heated leather seats.
2004 Jetta TDI

scoobysnax,
I just found the answer for my Liberty on page 269 of the 2005 owners manual. It indicates that the dealer can change the min/max pressure settings. I assume other years offer the same option.
Hope this helps.
Lewis

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Mail Rated 2005 Red CRD Sport with large rectangular hole in top right behind the EVIC and above the heated leather seats.
2004 Jetta TDI

Arguing on the internet is like being in the special olympics. Even if you win, you are still retarded.

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L.O.S.T. #050943
2002 Liberty Sport 4x4, Black
K&N FIPK, Drain pipe ram air
235/70-16 A/T Revo
Optima red top
Rancho RS5000, no lift
Hidden Hitch w/Yakima Bighorn 4 bike rack
Vent shades and deflector.

"In a time of universal deceit, telling the truth is a revolutionary act" - George Orwell

scoobysnax, try running 38lbs (cold) in them and see what happens. It should quiet the tpm sensors and give you better road contact.

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05 BLACK KJ - 42RLE & NP242
Skids, Hooks, Bent Rock Rail, Lifted, A/T's, etc.
NY and PA and Florida ONF Special Custom Organic Trail Rash

at 38 I was fine and that's what I've been running them at (they reach 40 once warmed up.) With the temps now getting into the 40's I need to add some more air. I'm back down to 35-36 from the change in temps. Never realized it had that much of an impact.

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'04 Liberty Limited - 245/70/16 Firestone Destination AT's, Mopar tow hooks, Draw-Tite Class IV hitch, Skid Row Engine & Transmission Skids, Mopar T-Case & Gas Tank Skids, Extended Breather Tubes, Red Top Optima, Sylvania Silver Star head lights, Hella 500FF bumper mounted driving lights

Wahoo,
Have you been waiting all year to say that?
Congratulations.
Lewis

Scooby,
It is easy to tell which tires have been sitting in the sun by the pressure, also interesting to watch the pressures as you go from garage to warm on a trip.

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Mail Rated 2005 Red CRD Sport with large rectangular hole in top right behind the EVIC and above the heated leather seats.
2004 Jetta TDI