BigCanoe

Hi, I recently purchased a 2002 Pathfinder. Here are the tires that are on it, and the pressures. Should I add more air?

Front:
Dunlop Grandtrek TG35 P255/65R16 (max PSI 51)
Left=31.5psi
Right=31psi

Back:
Goodyear Eagle LS (max PSI 44)
Left=28.5psi
Right=29psi

Not sure why they have different tires on front and back, but I assume this is ok.

Thanks

 

lewisnc100

If they are the same diameter it should be OK. But if they are different diameter or wear then getting out of 4WD can be difficult.

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1997 Pathfinder XE
Air Lift Air Bags, Warn Hubs

BigCanoe

They are all P255/65R16

Dirk Diggler

As long as they're worn about the same amount, should be ok. I believe you only need 26psi in them. Read the sticker in your glove box, my '01 with the same size tire requires only 26psi.

Joe.

pops55

If all tires are the same size (P255/65R16) or the larger pair is on the rear (presumably/usually for trailering) you should be OK. Tire air pressure is the biggest key to tire life. Although less air usually means softer ride, it will decrease wear mileage. On general purpose car & light truck tires I usually go 3-4 psi under-inflation, on heavier built tires I'll go 4-6 under (to allow for expansion when on hard surface road). Good thing to remember though, your vehicle is built on a truck frame/suspension, it's not a good idea to soften the ride by under-inflating tires, because you also lose handling & stability.

 

BigCanoe

So do you go by whats on the sidewall, or in the glovebox?

Frank1

My 04 LE says 30 on the door and 44 max on the tire. I have been running 38 PSI with perfect wear and ride.

greynolds

The numbers on the door or glovebox probably are not the optimum numbers to use. A few things to keep in mind:

1) Higher tire pressure will typically give you better gas mileage and make steering easier.

2) Lower tire pressure will typically give you worse gas mileage and make the steering feel heavy.

3) To much or too little tire pressure will accelerate wear on your tires.

4) To determine the correct tire pressure to use, there's a chalk test that can be performed. I don't remember exactly what to do (a google search would probably find the correct procedure to us), but the basic idea is you put your typical load in the vehicle, coat the tires with chalk and then drive it a short distance to get chalk marks to analyze. IIRC, what you want is a tire pressure that leaves a solid chalk mark pretty much the width of the tire, rather than a narrow chalk mark in the center (too much pressure), or marks on the outside edges, but a faint (or no) mark in the center (too little pressure). If you change the amount of weight in the vehicle (add a heavy bumper, carry more or less cargo than usual, etc.), you would have to run the chalk test again to determine the correct adjusted pressure.

The manufacturer of the tire or the vehicle is unlikely to be able to tell you the correct tire pressure to use because it depends on exactly what you're carrying for a load. The tire pressures provided on the doors by the manufacturer probably assume the stock tires (different brands/models of tires would require different pressures) and some sort of average or typical load in the vehicle.

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Geoffrey Reynolds
2005 Nissan Pathfinder SE Offroad

BigCanoe

Thanks, I heard something like the real max should be 10% below the tire max, so for me 40, I think I will try 38 after I read my door and glovebox for those numbers.

Dirk Diggler

Frank, are your rims 16" or 17"?

Joe.

 

pops55

GO BY WHATS ON THE TIRE. YOU MAY HAVE SOMETHING OTHER THAN WHAT THE CONSIDERS OPTIMUM FOR THE VEHICLE.

greynolds

What's on the tire is simply the maximum pressure the tire can safely hold without bursting. That should not be confused with what the correct pressure is for your vehicle. Correct pressure is a factor of the tire design and how much weight it has to hold up. The only reliable way that I'm aware of to determine proper tire pressure is the chalk test, despite it being a pain to do. The 2nd best way is to go with what the vehicle manufacturer recommends on the door/glovebox if you're using tires that are very similar to what came with the vehicle when it was new.

Certainly you should never exceed the maximum tire pressure printed on the sidewall of the tire, regardless of what the chalk test or sticker on the door tells you - if you need more pressure than the max the tire supports, you need to get new tires with the proper load rating for the vehicle.

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Geoffrey Reynolds
2005 Nissan Pathfinder SE Offroad

Frank1

My tires are 245-65-17

Dirk Diggler

Ok so that's why your glove box sticker calls for 30psi. Lower profile tires usually need more pressure... I have the 16" rims but with taller tires to maintain the same diameter, therefore only 26psi required... It does seem low though.

Joe.