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AUTO tire pressure

Old 06-14-06, 06:00 PM
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AUTO tire pressure

Know this is off topic, but figured many of us know a thing or 2 about bike tires, and perhaps someone here has knowledge about auto tires.

Our Minivan (Honda Odyssey 2002; front wheel drive) has different brands on front than rear. All tires share the following: P225/60R16 97S.
However as indicated on the tires, Max PSI is:
-front:44
-rear:35
Sticker inside door of van says cold PSI 36.

Should I:
1) run same (cold) PSI in all 4 eg 35?
2) 44 in front, 35 in rear?
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Old 06-14-06, 06:08 PM
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the sidewall is the last say. if it were me, I'd inflate according to what it says on the tires.
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Old 06-14-06, 06:21 PM
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Originally Posted by Bockman
the sidewall is the last say. if it were me, I'd inflate according to what it says on the tires.
Yeah, that's what Firestone said.

I would go with the vehicle suggestion. The tire manufacturer has a vague idea which general type of vehicle the tire is likely to go under. The vehicle manufacturer tells you what size and how much pressure.
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Old 06-14-06, 06:21 PM
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You've also got mismatched tires there. My experence with Honda Odysseys say match the tires.
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Old 06-14-06, 06:38 PM
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Vacation travel starts 5am tomorrow. Gotta do my best w/ these tires for now, even though mismatched.

Rear 35-36.
Front 35-36 (auto rec) or 44 (tire rec)?
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Old 06-14-06, 06:49 PM
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44 just seems odd for a passenger tire recommendation. According to this consumer guide you should follow the car placard. Same from the Washington Post car guys.

Via Magazine
AAA and here
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Old 06-14-06, 07:06 PM
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Originally Posted by twahl
44 just seems odd for a passenger tire recommendation. According to this consumer guide you should follow the car placard. Same from the Washington Post car guys.

Via Magazine
AAA and here
Thanks, read the links which were helpful.

The van itself recommends 36psi cold.
Rear tires say 35 MAX psi.
Front tires say 44 MAX psi.

We had 2 tires need replacing after only 15k miles. After some haggling my wife did with the dealer (YES, the dealer......) they agreed to sell us tires at 1/2 price, supposedly. My guess is these new tires (now on the rear) are of lower quality, and thus have a lower MAX psi compatibility. These new tires have lower MAX (35) than the auto sticker recommendation (36).

Shop we bought the tires now closed. Until able to talk with them, will go w/ 35-36 for all 4 tires per Honda rec.

We bought an air compressor which is quite nice! I plan on optimizing our tire pressure on a much more regular basis.

Thanks to y'all for responding.
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Old 06-14-06, 07:39 PM
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pfffffft.... pump those puppies up to 120psi like a real roadie
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Old 06-14-06, 07:58 PM
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keep the tire pressures the same all around, unless your auto-xing or drag racing the minivan
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Old 06-14-06, 08:05 PM
  #10  
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Follow the placard for best handling/ride.

If you're out for better gas milage--like myself--go to the sidewalled max +10%.
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Old 06-14-06, 08:27 PM
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It sounds like the load rating on the front tires is going to be a lot higher than the rear tires. It's quite possible that the new tires do not have the correct load rating. It's on the sidewall, check it out.

If the load rating is significantly lower than it should be, (according to the owner's manual) this can create a blowout which on a front wheel drive minivan could be very dangerous. For example, a required load rating of 98 and an actual of 96 or 97 probably won't be a big deal, especially if you're not running fully loaded. But if the requirement is 98 and you've got 94, it could be very dangerous for your family to be hurtling down the freeway at 80mph on a hot day and have the tires suddenly blow out. This is not a safety nazi fantasy or lawyerese, this is a fact.

At any rate, if you replace the tires with the correct size and type, you should always follow the inflation pressure advice printed in the owner's manual of the van, or printed on the door or glovebox door.

Az
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Old 06-14-06, 08:32 PM
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Originally Posted by nocondorfx
keep the tire pressures the same all around, unless your auto-xing or drag racing the minivan
Nothin' wrong with drag racing a minivan. Mine would pull 16s all day long
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Old 06-14-06, 08:36 PM
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Originally Posted by Az B
It sounds like the load rating on the front tires is going to be a lot higher than the rear tires. It's quite possible that the new tires do not have the correct load rating. It's on the sidewall, check it out.

If the load rating is significantly lower than it should be, (according to the owner's manual) this can create a blowout which on a front wheel drive minivan could be very dangerous. For example, a required load rating of 98 and an actual of 96 or 97 probably won't be a big deal, especially if you're not running fully loaded. But if the requirement is 98 and you've got 94, it could be very dangerous for your family to be hurtling down the freeway at 80mph on a hot day and have the tires suddenly blow out. This is not a safety nazi fantasy or lawyerese, this is a fact.

At any rate, if you replace the tires with the correct size and type, you should always follow the inflation pressure advice printed in the owner's manual of the van, or printed on the door or glovebox door.

Az
Vehicle sticker recs P225/60R16 98T.
All 4 tires are P225/60R16 97S.

This weekend we are travelling light except for ourselves.
However in 3 weeks will be going to beach loaded down; 8 hr drive with 5 bikes on the rear (hitch mount). No trailer. Think the 97S's will be ok? The 2 tires are only couple mos old, dang......
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Old 06-14-06, 08:37 PM
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Air compressor? I use my bike pump.
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Old 06-14-06, 08:39 PM
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Originally Posted by kuan
Air compressor? I use my bike pump.
Wife more likely to participate
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Old 06-14-06, 08:41 PM
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Unless you are planning on travelling at 112mph+ for extended periods of time and/or carrying VERY heavy loads, the difference in rating of those tyres is almost inconsequential.

I would inflate them to 36psi cold (add 2 psi for extra load) and have a good holiday.
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Old 06-14-06, 08:48 PM
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Originally Posted by 62vette
Unless you are planning on travelling at 112mph+ for extended periods of time and/or carrying VERY heavy loads, the difference in rating of those tyres is almost inconsequential.

I would inflate them to 36psi cold (add 2 psi for extra load) and have a good holiday.
Looks like you are correct!:

http://www.tirerack.com/tires/tirete....jsp?techid=35

97 1609 lb
98 1653 lb

S 112 mph
T 118 mph
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Old 06-14-06, 08:50 PM
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The difference between 97 and 98 is only 50 lbs per tire. So if you're 200lbs less than gvwr, you're fine. The Odyssey is rated for something like 3/4 of a ton, so you should be able to pack it pretty full with no problems on those tires.

One thing to consider is that the tire's max load is based on the max psi printed on the tire's sidewall, so I would run maybe 38-39lbs in the front tires when you're loaded down. The rear will be fine at 35. Never exceed the sidewall's max rating.

Generally, better tires will give you better peformance on a heavier vehicle, like a loaded minivan. I like to use tires with more sidewall reinforcement with top heavy vehicles. It's likely that your rear tires are not reinforced, and your front tires are, and that's why the front can run higher pressure. You may notice the rear end blowing around more in high winds or when passing/being passed by big trucks, etc.

But the bottom line is that you should be fine, but keep a close eye on the tire pressures. That's good advice for anyone travelling this summer really.

Have fun!

Az
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Old 06-14-06, 09:07 PM
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Van sticker says GVWR is 5600# (2300front, 2300rear)

Does this mean each tire needs to have at least load index of 86 = 1168# ?
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Old 06-15-06, 05:07 AM
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Stick with the sidewall rating. The auto manufacturers rating is ONLY applicable to the OEM tires, once you change brands/types, that sticker no longer applies. Also, they recommend a very low pressure because it improves the 'feel' of the car and prevents it from being rough and bumpy.

I always follow the sidewall rating and will typically inflate to 2-4psi below max, depending on the conditions.
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Old 06-15-06, 06:07 AM
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Auto engineers post tire inflation ratings on vehicles for a reason. That's what gives the vehicle optimum handling, braking, and ride characteristics. Too much inflation, especially in the front, may severely affect your handling especially in emergency situations.

Go with 35/36 all around.
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Old 06-15-06, 06:17 AM
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Originally Posted by nocondorfx
keep the tire pressures the same all around, unless your auto-xing or drag racing the minivan
On THIS vehicle thats what you want to do, but only because its what the manfacturer recommends. If Honda said to inflate the front or rear tires more - thats what you should do. Its not that uncommon, and doing anything other than what the placard says could be asking for more trouble than if you just leave them how you've been driving on them up til now. I know for a fact that my car recommends something like 3-4 more PSI in the the front than in the rear. It could be due to the fact that my car has a big V6 shoe-horned in a compact, two door car - but I know other cars are the same way.

the sidewall is the last say. if it were me, I'd inflate according to what it says on the tires.
The sidewall isn't the last say, thats completely wrong. The placard is the last say, but I wouldn't exceed the maximum PSI for the tires. But since the max rating is within 1 psi of suggested, you'll be fine just filling all 4 tires to 35-36 PSI cold. That one less psi / one more over the maximum rating isn't going to cause anything to happen.
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Old 06-15-06, 06:41 AM
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Originally Posted by TJHOO
Van sticker says GVWR is 5600# (2300front, 2300rear)

Does this mean each tire needs to have at least load index of 86 = 1168# ?
If the van was completely static all the time, yes. But there are many dynamic loads while driving... turning, stopping, hitting potholes, etc. So the engineers determined that 98 gave a good margin for these dynamic loads and other variables.

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Old 06-15-06, 08:19 AM
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Folks, I think that if you'll do a little research, you'll understand that the sidewall is only the last word on maximum pressure for the tire. This may exceed the maximum for the vehicle. Remember the whole thing with the Firestone tires and the Ford Explorers a couple of years back? The problem was people inflating to the tire recommendation, which exceeded the vehicle recommendation. We aren't talking about a bicycle here, where the weight of the bike is a negligible factor in the big picture, we're talking about a vehicle where the weight of the vehicle is the single most significant factor in the big picture. Please do some research, and back up your words with something other than your belief before you give someone advice that could put their family's lives in danger.

The idea that different brands and types of tires make the manufacturers recommendation irrelevent is ludicrous. In one example, I can tell you that my vehicle comes from the factory with at least three different tires depending on the trim level. The vehicle doesn't come with different tire pressure placards.
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Old 06-15-06, 08:22 AM
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I've always run within 2 PSI of the max on all my vehicles. The ride *may* suffer, but the tires run cooler, last longer, and you get better fuel economy. Tires don't carry the amount of weight they are rated for until they are at max PSI.
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