My 2006 Jeep has Goodyear Wrangler SRA tires and the door jam states 33lbs PSI cold.My dealer(Jeep)put them up to 35 1/2 cold.I'm looking for a all year round cold tire pressure.Which is correct?
Thanks Joe
Tire pressure-33 lbs PSI or what?
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I would treat the door sticker as a low starting point. From there, you could increase it a few PSI for slightly better MPG, but if you find the ride too harsh, then you may come back down to 33. Higher PSI should also give you better steering response, but depending on the sidewall height, you may not notice much difference.
Your Jeep only list one set of tire pressures? I heard newer cars list only the full load pressure and no longer have half load listed.
I usually run 1-2psi over the sticker on the door. So if it list 33psi all the way around, I would run 34-35 psi to account for the error of the tire gauge.
I usually run 1-2psi over the sticker on the door. So if it list 33psi all the way around, I would run 34-35 psi to account for the error of the tire gauge.
Close enough. I fill just over often enough just trying to allow for tire heat from driving in to the dealership. So say the door says 33 and I fill them up and and find one at 35, I fill them all to that. Assuming tire heat.
Quattro Pete has the idea, as long as you monitor tire wear to boot.
Quattro Pete has the idea, as long as you monitor tire wear to boot.
How much you can go up will depend upon what the max pressure is for your tires. I noticed that the newer tires on our cars have a 44 psi max, compared to the 35 psi max on the ones that we use to have.
Look at your vehicle weight and check what the max pressure is on a pickup of similar weight. SUVs seem to spec lower psi for comfort, which should be a secondary concern on a heavier vehicle. If you have a larger vehicle that has the ability to carry a fair payload and different tire pressures aren't spec'd, be concerned.
Look at your vehicle weight and check what the max pressure is on a pickup of similar weight. SUVs seem to spec lower psi for comfort, which should be a secondary concern on a heavier vehicle. If you have a larger vehicle that has the ability to carry a fair payload and different tire pressures aren't spec'd, be concerned.
That 2-1/2 pound difference can easily be due to an inaccurate gauge. I check my gauges against the tire guy at the racetrack a few times a year.
By a good inexpensive digital gauge and check them before the vehicle is driven in the morning (cold air pressure)at least once a month if not more often.
Remember, a 10 degree rise or drop in outside temperature = a 1 PSIG rise or drop in your tire pressure.
If you try and check them after the vehicle is driven, you will not get accurate readings as driving heats up the tires!
I would go with 35 pounds too.
If you don't have an air compressor at home, just before going home in the evening use your digital gauge and pump them up to about 3 or 4 pounds over where you want them. You then can adjust them the new morning for accurate readings.
Never go over the safe cold max rating on the side of the tires. Even in the same brands, different tires have different safe max cold ratings.
Remember, a 10 degree rise or drop in outside temperature = a 1 PSIG rise or drop in your tire pressure.
If you try and check them after the vehicle is driven, you will not get accurate readings as driving heats up the tires!
I would go with 35 pounds too.
If you don't have an air compressor at home, just before going home in the evening use your digital gauge and pump them up to about 3 or 4 pounds over where you want them. You then can adjust them the new morning for accurate readings.
Never go over the safe cold max rating on the side of the tires. Even in the same brands, different tires have different safe max cold ratings.
. . . then follow this link: One of the least expensive but very valuable accessories one can buy: every home with a vehicle should have one.
For touching up a few pounds of air in the cars I use a foot pump with a section of good hose and a good self clamping connector. I've had it for years, and a couple of times have taken it apart to clean and grease it. I tried a 12V pump but it was REAL loud and worked SLOW, so I gave it away. For the truck I have a Dewalt continous duty air pump, bought used from a neighbor in construction, and although it's also loud it at least works well.
Leave it at 35psi, probably have slightly better wear/gas mileage.
My Rodeo calls for 32 x 4, I run them at 38 frnt/40 rear with excellent wear, mileage, and cornering. Even Discount tire refuses to set mine back to 32psi, rather 35/40 is what I find that they do.
My Rodeo calls for 32 x 4, I run them at 38 frnt/40 rear with excellent wear, mileage, and cornering. Even Discount tire refuses to set mine back to 32psi, rather 35/40 is what I find that they do.
Check tires after driving, too. If one of them is warmer than the others, but the pressure is good, you have a problem.
sticking brakes
my F150 shows only 30 in the front and 35 in the rear! I run them both at 40.
darn it!!! I found the same model, but with the cord. but the little woman fell in love with the auto-shutoff feature (then again, so did I)
Here's one with a power inverter, all for under $40!!!
http://www.walmart.com/catalog/product.do?product_id=3992
howdy there fellow rodeo owner! (I've got a 95 rodeo!)
I think it is worth mentioning that it is a very common misunderstanding that an SUV or truck should have higher pressure in the rear. This is false. I've had guys who work in tire shops tell me they recommend higher pressure in the back of pickups and stuff. This is VERY false for 90% of usage.
If you load the back of the vehicle down, then running more pressure is important. (like say, 400lbs tung weight from a trailer, plus 1000lbs of cargo piled in the back). Otherwise, running really high pressure in the rear will only serve to make your contact patch much shorter and somewhat more narrow, and put most of the wear and load on the center of the tread pattern.
The front and back of vehicles really SHOULD be treated as separate entities when airing up. Knowing the approximate weight on the axle would really be best.
The best method for finding appropriate tire pressure in light truck applications that I have found is as follows:
Take the weight on the axle, divide by 2.
Take that number and divide it into the maximum load rating of the tire(on sidewall).
take that result and multiply it by the maximum tire pressure on the sidewall.
This is your tire pressure. You'll find that if you have a good accurate (estimate even) weight per axle, and you average your 2 results, it'll always come VERY close to the number on the inside of your door. Unless you drive a ford, where they like to break these rules to give a smoother ride while wasting more fuel and exploding more tires on the highway.
When figuring weight, you could probably take the dry weight of the vehicle(can't remember what that weight is called, but it should be listed in vehicle specs somewhere), and add a few hundred pounds(400-600) for typical passengers, fuel, and spare tire loads. then subtract some from the rear and add some to the front..(this is an estimate, but taking true weight wouldn't hurt)
This method is great for recalculating an appropriate pressure when you install over-sized or undersized tires on a light truck. I tend to add a few pounds to this result just like most people to get a hair better fuel economy.
I'll give an example to clarify.
5000lb pickup with empty bed
front axle 3000lbs
rear axle 2000lbs
Tire: Goodyear Fortera SilentArmor 31x10.5R15
C load range, 2270lbs max, 50PSI max.
Front axle: 3000lbs/2=1500lbs(per tire).
1500lbs/2270lbs=0.661
Rear axle: 2000lbs/2=1000lbs(per tire).
1000lbs/2270lbs=0.441
Front: 0.661x50PSI=33PSI
Rear: 0.441x50PSI=22PSI
When a manufacture rates a tire for load and PSI, they are saying that at the maximum inflation pressure, the tire can hold the maximum rated load and will have an even contact patch and be safe to drive. The amount of air in the tire is almost directly proportional to the load capacity. This is why tires with higher load ratings have higher pressure ratings, and they must be run at higher pressures if you increase the load.
Here's an example of a rodeo:
I've figured with my tools and a passenger or 3 and a full tank of gas, I'm sitting at around 4500lbs on average, with around 2100lbs in the rear, and about 2400lbs in the front.(aprox) My door-panel sticker says 245/70-16 tires, 29PSI.
example: BF AT KO 245/70-R16, load range "D", 65PSI max, 2535lbs max.
front: 2400/2=1200, 1200/2535=0.473, 0.475x65=~31PSI
rear: 2100/2=1050, 1050/2535=0.414, 0.414x65=~27PSI
31+27=58(taking average of 2 here), 58/2=29PSI (the recommended PSI on my door), coincidence?
When following this guidance, I would highly recommend inflating the rear whenever you are loading it down, if you are really going to load it down big time, just air up to the max on the sidewall for the afternoon till you unload your boulders. This will keep temperatures down on the highway, and keep the likelihood of blowing a tire to a minimum.
need to RE-iterate something... I mention that the amount of air in a tire is ALMOST directly proportional to the load capacity, the ALMOST really should have been in BOLD. because it is certainly not linear(it's more like a wavy line, lol.) For example, a tire with only 1 PSI in it would not behave according to the example above very accurately (would have ~40lb max weight capacity)... but since the tire weighs 40lbs already, well, you get the picture... there's more to it, bleh, nuff said.
Someone correct me if I'm wrong here but isn't one of the reasons for higher rear tire pressure to help correct the vehicle's dangerous tendency to oversteer? Decreasing rear pressure would increase this tendency and make for a dangerous ride.
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