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Discussion Starter #1
I found that if I reduce my tire pressure to 29 psi intead of the regular 32 psi, when the SUV is cold, improved the performance. If you start at 29 psi when cold the tire, at least on the touring-Michelin tires, heat up to 31 once they hit normal operating temperature. If you start at 32 psi when cold it reaches 34-35 psi which maks for a firmer ride over bumps. I notice a significant difference especially in New York City where the roads are much bumpier. Try it makes a big difference. The gas mileage has been the same about 13-22 depends on conditions.:D
 

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Old School

I guess I am from the old school. The higher the inflation, supposedly the better the dry weather cornering. In fact with a "front driver" like the X, the front tires should be a few pounds higher than the rear to avoid front drive understeer- having said that, I have a funny feeling the VTM-4 makes this all moot.
 

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Discussion Starter #3
Old School always right!

Definitely agree with your comments it does increase traction in dry weather. I was so impressed with the smoother drive when I dropped just the slightest, I can't seem to get use to going back to the 32psi. It's amazing how much a difference those 3 psi make. Much more like a towncar drive of a lincoln!:D
 

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I'm somewhat worried that underpressured tires might cause front tires to wear out faster especially when MDX is mostly in front wheel drive mode. These tires aren't that cheap either...
 

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One of the big problems with the Ford Exploder tires was that they were underinflated (I think they called for 25 lbs?) for a better ride. Problem is, the more underinflated the tire, the more heat it generates. I think I would stay at what Acura recommends.
 

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there's underinflated and then there is...

Markedoc said:
One of the big problems with the Ford Exploder tires was that they were underinflated (I think they called for 25 lbs?) for a better ride. Problem is, the more underinflated the tire, the more heat it generates. I think I would stay at what Acura recommends.
I think that 29 vs 32 is within the error range of many tirepressure gauges...

If you are running with with significantly less than the recommended pressure it is going to contribute to tire FAILURE, (and even then testing by Car & Driver suggests tire failure doesn't automatically result in Explorer rollover...) but 10% ought to be acceptable, ESPECIALLY around town, where the road hazards/conditions are more likely to contribute to accelerated tire wear.

Finally, when I worked in a big shop (way back in college) I learned that when folks said they wanted a bike that was "fast" it was best to fill the tires to max pressure, but if folks wanted "comfy" it was best to adjust air pressure to a minimum ( and tell 'em we'd fix flats for no charge if they bought a tube from us...)
 

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Re: there's underinflated and then there is...

renov8r said:


I think that 29 vs 32 is within the error range of many tirepressure gauges...

So ... if you have a 3 lb error range and you set your inflation pressure at 29 lbs, you might have 26 or 32.

And what do you lose - 1 lb for every 10 degree drop in temp?

I'll keep mine at 32.
 

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Discussion Starter #8
definitely don't underfill

I agree that if you put to little it is dangerious and can cause the tire to overheat or cause permanent damage to tire, like in the exployer. I would only drop to 29 psi, so that when tire heats up to 31 psi it drives a little smoother. I use a more expensive digital tire gauge which is accurate to Plus/minus .05 psi. I would not go any lower than that, make sure when tire heats up you are at least 30 psi or over. It's amazing how much a difference 2 psi makes in the driving over bumps. If you like the firmer drive then go with the factory settings. I'm sure it will cause the tires to wear a little faster than the 32 psi setting, but I have family in the auto business and can get parts at cost. Again it's a matter of what type of drive you like. :D
 

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Re: Old School always right!

paul123 said:
Definitely agree with your comments it does increase traction in dry weather. I was so impressed with the smoother drive when I dropped just the slightest, I can't seem to get use to going back to the 32psi. It's amazing how much a difference those 3 psi make. Much more like a towncar drive of a lincoln!:D
Actually it doesn't increase traction. The more air you put in, the smaller the tire contact patch gets. That's why people driving in sand (low speeds only) deflate their tires, so as to get a wider contact patch and to be able to "float" over the sand rather than sink in.

Higher tire pressures will help to decrease the wear on the edges since there is less tire flexing. Less tire flex will also mean slightly less body roll, but you'll have to jack up the tire pressure quite a bit to notice the difference.

As for understeer and oversteer, raising the front tire pressure will lessen some understeer, but will increase oversteer. Remember that the MDX is already nose heavy. So, it all comes to a balancing act.
 

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Low OK, Pressure Increases ??

When mfgs set the recommended pressure, they are aware that the tires will heat up and pressure will rise.

Based on all the stuff I've read about Ford and Firestone, no way will we run at less than recommended pressure. Don't know the extent of risk; however, ANY INCREASED RISK is too much for my liking.

Any tire can pick up a nail and air loss can occur. Even if the extra air is simply a safety margin, guess it's a margin I prefer to have. Precious cargo on board!!
 

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Pressure already minium

In regards to tire pressure, the manufacture selects the tire pressure with several criteria in mind, load capacity, handling, heat build up & riding comfort to name a few. In general, I think they set it on the low side for riding comfort.

Therefore, I would not set my tires below the specified pressure and may even add one or two pounds for better handling, tire wear & milage.

Remember when you used higher pressure for extended highway trips than normal pressure but maybe modern tires don't require this adjustment anymore.

Since I do 75% highway, I will keep mine at 32+.
 

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Slightly off the topic......

paul123 said:
I found that if I reduce my tire pressure to 29 psi intead of the regular 32 psi, when the SUV is cold, improved the performance. If you start at 29 psi when cold the tire, at least on the touring-Michelin tires, heat up to 31 once they hit normal operating temperature. If you start at 32 psi when cold it reaches 34-35 psi which maks for a firmer ride over bumps. I notice a significant difference especially in New York City where the roads are much bumpier. Try it makes a big difference. The gas mileage has been the same about 13-22 depends on conditions.:D
...........but I thought it might be interesting to mention. The recommended cold tire pressure in my 4-Runner is 32psi, but I'm always riding around with the tires at around 26psi......otherwise I will have to replace the bones in my body in a few years instead of the car :D :D :D :D ..........and I'm only 28 years old!!! :D :D
 
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