Optimal Tire Inflation Psi
 

I am still riding on stock tires and wheels. I will keep the stock wheels but will likely replace the tires at some point when they need it.

Right now the tires are still inflated to door jamb numbers. 32/33 I think.

Has anyone experimented with different inflation numbers on their Fit? I expect you could pump more air in and get better mileage and likely better tire life. Too much and the tires only wear in the middle and the ride suffers.

Is there a better psi to run?

On other cars I have run the recommended pressures and kept track of tire wear across the width of the tread.

Invariably, the front tires wear on the edges more than the middle so I adjust the pressure upward., usually about 8 PSI higher than recommended. This seems to make the fronts wear evenly.

The rears don't wear much at all regardless of pressure.

I asked this in the preferred psi thread:
Do I recalibrate the TPMS or not? Is the TPMS just a floor at 25 psi that you don't want to drop below?

I don't know what you mean by 'recalibrate the TPMS' but the TPMS simply measures pressure and when it drops below a pre-set amount (I've heard 10% under recommended pressure, probably in the high twenties) then it triggers. If you run the tires up to 40 psi the TPMS doesn't care, it'll still alert you only when it drops below where they're set.

Not correct. The tire pressure monitoring in the new fit is not measuring tire pressure at all, but rather the difference in rotational speed of each wheel relative to what it was when calibrated.

So in Answer to the original question, Yes, if you run higher tire pressures, you should re calibrate the TPMS.

I have found better fuel economy can be found with 40 psi+ pressures! but it also has a negative affect on the ride of the car.

From this page:
http://owners.honda.com/vehicles/inf...m-%28TPMS%29/3








Tire Pressure Monitoring System

An underinflated tire can impede handling and can be a safety hazard, so the Tire Pressure Monitoring System (TPMS) uses pressure sensors mounted in each wheel that send readings to a central electronic control unit to help you stay prepared. The system evaluates whether the pressure is at an acceptable range. If a reading is approximately 25% below the recommended level, the Fit will alert you through a warning light on the instrument panel.

And yet the owner's manual says:
Instead of directly measuring the pressure in each tire, the TPMS on this vehicle
monitors and compares the rolling radius and rotational characteristics of each
wheel and tire while you are driving to determine if one or more tires are
significantly under-inflated. This will cause the low tire pressure/TPMS indicator to
come on.


Sloppy that it contradicts...

"The 2015 Fit manual" shows how to recalibrate the TPMS. Little tricky, but one has to do it right each time one changes the tire pressure.

That's why it says:

Frankly, I'm happy that the new Fit has sensorless TPMS. The prospect of having to deal with sensor at tire change time, "Gee, sir, we "accidentally" broke two of your sensors but new ones are only $100..." was really not attractive to me. As long as I can recalibrate the sensors whenever I want I am happy.

Yes, but that info was on the 2015 Fit page specifically. So I'm sticking with 'sloppy.'

Thank you for the tip!I noticed, the tires are worn out at the edges on two different cars, and different brand tires. I never had "underinflated" tires. For me it means to comply the spec. But now I realize, there is something wrong. Tire manufacturer or car manufacturer is wrong?

Gen 3 Honda Fits have the passive TPMS system, so yes, you need to recalibrate anytime you rotate tires, change tires, or change PSI. It's really easy.

fixed.


10char

Unless I keep my Yokahamas at 40psi, my low pressure light comes on.. No adverse tire wear or hit to MPG

I wish I didn't have to do it.
But the recalibration process is really easy.

Is there a holy grail? I got to find out. Opinions just don't do it for me.

unless you're taking about the donut where it says 'inflate to' the psi stamped on the sidewall is usually the max psi the tire can handle. its waaaay too high for a Fit.. well, im sure the hypermilers dont care and use it anyways.

there are just so many better ways to save money and be eco-friendy.