# Thread: Right Tire pressure OR overinflation??

1. ## Right Tire pressure OR overinflation??

Hi

I have a 2003 hch which gives me around 44-46mpg according to the guage but according to tankfull to tankfull calculation gives only 40-41mpg.

I have the tire pressure all around to be 32psi. I have read that increasing tire pressure will increase the mileage ....so my questions are

1> What kind of mileage increase are we talking about if I go upto 42psi in each tires?
2> Does it increase the probablity of hydroplaning if its overinflated.
3> Will overinflating reduce the overall tire life. My front set only lasted 30k miles.
4> will there be uneven wear of the tires which will cause me to change tires sooner.. which will be more expensive than the fuel cost savings got by overinflation.

I am sure there will be bumpy ride due to overinflation but I dont really mind.

Hope someone who has tried it for long enough gives me some answers.
Thanks

2. ## kangaroojack: 1- Increasing

kangaroojack:

1- Increasing the tire pressure could lead to a significant increase in mileage depending on speed and the nature/condition of the road surface. For the average person it can amount to 5-15 MPG or even more in some cases.

2- Quite the opposite. The likelihood of hydroplaning is greatly reduced with higher tire pressures.

3- Again the the opposite is true. The tire life is extended if we pump the tires up to 40psi or max_pressure.

4- Uneven wear in current technology tires is more commonly the result of mis-alignment. But even under a condition of mis-alignment the tire wear is still greater with lower inflation pressures. A long time ago, tires were known to wear in the middle if over-inflated but those theories are no longer current or valid.

All of the above answers were provided for conditions where the tire pressures do NOT exceed the maximum rated pressure for each tire.

Cheers;

MSantos

3. ## Will up the pressure to

Will up the pressure to 42psi and see what happens. Will update this topic when I know the difference in mileage.
Thanks again for answering all my questions Msantos

4. ## Something *very* insigficant

Something *very* insigficant I've been musing about: upping tire pressures must be causing a *slight* increase in circumference.

We keep ours at around 38~40 psi. The ride is a little harsher, and one concern I have, if you're for example rounding a corner with tire ruts, your odds of *losing* contact with road momentarily must be up a bit.

5. ## Will the wear and tear on

Will the wear and tear on the car will be geater with overinflated tires?

6. ## If the road conditions are

If the road conditions are anything but smooth then yes, there will be more wear and tear on the vehicle since the suspension will have to work harder to overcome the roughness of the road surface.

However, the definition of over-inflation is technically only applicable when we exceed the maximum rating of a tire (44psi). Since we all have different requirements, that gives everyone a chance to press their tires from the manufacturer recommended 32psi all the way to 44psi.
Most people will find the sweet point anywhere from 38 to 42psi which is not over-inflation and still a good compromise between fuel economy and comfort.

Cheers;

MSantos

7. ## On the subject of tires, my

On the subject of tires, my 06 Hybrid needs tires. I would appreciate input on what owners have been using to replace the OEM Dunlop tires. I have 31K and they are fairly noisy. Thanks

8. ## Rear tires are scalloped on

Rear tires are scalloped on inside edges (less then 10,000 on 2008). Dealer said this was do to tires being over-inflated, to 40psi and won't check alignment. BS or true?
Thanks

9. ## Fully qualified BS. Tell

Fully qualified BS.

Tell them to check a TSB on the rear control arms and have them replace the arms ASAP. Also, go see another dealer as your present dealer is behind on training and sensibility.

Cheers;

MSantos

10. ## It depends upon the road

It depends upon the road condition and terrain you are driving in.They also make up a influence on percentage of air in the tire. You should also calculate this factors.