Optimal Tire pressure Prius 2010

I'm not sure if it's "optimal", but many of us seem to use 42psi in the front and 40psi in the back. It makes the ride a little harsher (not significantly to my mind) and seems to enhance mpg. You could try taking it up to 38/36 and see how that feels to you and go up if you're comfortable with it. Some take the psi up higher, but I'm happier being under the max rating on my tires (44). I think there are some other threads about this if you do a search.

 

Do you guys use your own air compressor or use the local gas station? If you have an air compressor, do u have any suggestions? Looking for a digital version to get my tires inflated to the precise amount.
Thanks!

 

Don't sweat the air compressor gauge. Get an accurate easy to read handheld gauge and live with whatever comes with the air compressor. When you fill you tires, fill them one or 2 psi over with the crude air compressor gauge, then bleed them down to your desired pressure with your hand held gauge.

Accurate hose mounted air compressor gauges are hard to find, expensive and get knocked around because they are on the end of the hose.

I use this cheap but rugged gauge on my air compressor.
Dual Angle Chuck Tire Inflator. You can read it to 1 psi, mine appears to be accurate to about 1 to 2 psi, which is good enough for some people.

I use still use a better hand held gauge to set final pressure.
Google Michelin 12279. I have that gauge except with
the Accutire brand name on it. I had it checked by a friend in a cal lab. Mine was well within 1 psi accuracy at normal tire pressures and can be read to 0.1 psi.

 

Thanks for the tip about which guage to pick, but no one has really answered the question yet...?!?? What is the best/optimal tire pressure for the Gen III Prius? More importantly WHY and are the more that one settings...? Should the "FACTORY" settings listed on the driver side sticker used?

One post said 44psi but it wasn't clear if that was the "optimal" tire pressure or of that was a preference...? What about wear/tear on the tires themselves...?

Sorry if the answer is obivious to everyone else but I'm still a NOOB on the Prius thx!

 

Optimal for who under what conditions?

No one can begin to tell you what is the best/optimal tire pressure for your car until you tell us which characteristics are most important to you along with some indication of how important the less than most important characteristics are. Also what your driving conditions are.

You can't go wrong with the factory settings. Anything up to the pressure on the sidewall is safe.

Higher pressure will make the ride harsher and increase fuel economy. Pick the compromise that suits you the best.

About mid-way between the two suits many people.

 

In order to maintain tire pressure at my convenience, I pump at home.

I use a bicycle floor pump. It takes a long time only the first time if adding a lot more pressure. For periodic pressure maintenance, it takes only a few strokes per tire. My 12V compressor takes longer to re-stash the power cord that it takes pump hand-pump the tires with the hand pump.

Many other folks already have 120V compressors for other uses, so obviously those are more handy than a bicycle pump.

 

Thanks xs, for putting things into perspective. This is/was the EXACT clarification, I was looking for. There is NO perfect setting for optimal TP, it is user preference and individual driving conditions that will dictate the settings. Your suggestion to set TP for somewhere between FACTORY and MAX is a perfect baseline to start my own research.

 

It depends on to many variables, one set of pressures may work well in some tires for some drivers in some areas. One thing for sure, an engineer in an office building in Japan, who may not even own a car, can't possible know what the best tire pressure is for all conditions. I suspect the recommended pressures are designed to provide a comfortable ride and good dry weather braking for some car on a test track in Japan when the ambient temperature is an ideal 70 degrees F, or something like that.

The recommended tire pressures are apparently not included in the formula that is used to compute fuel mileage estimates for the EPA requirement. I suspect from my own experience and from most others on this site that the best pressure is going to be between the recommendation and the maximum load pressure printed on the sidewall.

Tire wear doesn't seem to be a factor, tires no longer wear out in the center if you put higher that recommended pressure in them. I have been running between 42 and 48 lbs in my tires for 30K miles now and they are wearing pretty evenly, maybe a little more on the edges due to cornering forces.

I prefer higher than Toyota's recommended pressures because it gives me better handling, higher resistance to hydroplaning, and better fuel mileage.

 

Not sure what optimal is, but I keep my tire pressure at 40psi (Front) and 38psi (Rear).

I personally never trust the people at tire shops to check my tire pressure, there are too many inconsistencies! I would also highly recommend that you purchase a good tire pressure gauge (not a pencil gauge) and a portable air pump. I bought a cheap portable air pump at Walmart for about $15.00. It saved me a lot of time & money in regards to driving to the gas station, with a bunch of quarters, in the hopes of adjusting my tire pressures before I need to put more quarters into the stupid machine!

 

@Theotherone - Any reason why you have two different pressures higher in front than rear? Is this somehow better than the same pressure for all 4 tires? thx!

 

The front of the car is considerably heavier than the rear of the car. Withing tire sidewall pressure rating, more pressure, more load capacity. Car manufacturers also select tire pressure differences to give desired handling characteristics.

 

@XS - Thanks for coming to the rescue again...

 

I have been running 50/48 PSI on mine for the last 35,000 miles. It drasticly helps with MPG's. I average about 62MPG a tank. The tires do not show any wear with that many miles on them.

 

Those look good for 35K, I think my wider ones are going to be lucky to get to 40K but you should go well beyond that.

 

Based on the Toyota's recommendations, the tire pressure is recommended at 35psi (Front) 33psi (Rear), which is basically a two pound bias. I believe this has to do with the heavier load the Prius tends to carry in the front of the vehicle.

Therefore since I tend to increase the tire pressure about 5psi all around, I used Toyota's recommendations as something to start from.

 

Hey Judgeless,

Nice PIC, looks like your tires are holding their own pretty well!!! Which tires did came with your car, bridgestone ecopia or another make/model?

My IV was delivered with Bridgestone ECOPIA tires... MAX pressure on the tire is listed as 44psi max, I've now set the tires to 40psi... It was delivered with the tp set set @ 36psi.

Is 40psi to "close" the to max and should I back it off?

 

Mine are also Bridgestone ECOPIA tires with a max PSI of 44PSI. I run them at 50/47PSI all the time. When they build tires they spec them a lot higher than the max PSI.

If you start seeing a wear pattern in the center of the tire and not the sides you have to much air in your tire. At 50/47 PSI I have not had that issue with these tires. Having more pressure creates less drag for better MPG’s.

 

The front of the car weighs more than the back. The different PSI ratings balance everything out. If you do not fill the front with a higher PSI you will notice the car drives a lot different.