Best tire pressure for the Prius C?

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Ha!! You should see some of our roads here in Honolulu. Always under repair, repaired poorly and often full of potholes. Some holes so big the local news sometimes televises the areas and shows the holes on the evening news.

 

I hear ya regarding Hawaii! I rented an MX5 or a Miata as you guys call em when visiting Maui a few years back. Kept it for a few days then picked up a Wrangler!

Both were good fun fir different reasons, but I was glad that I had the Jeep for the road to Hana

 

Tony D:

The road to Hana is something else but the scenery is beautiful.

There is or was a back road to Hana - well "road" is really stretching it.

My friend took us on that road once in his '69 Bronco four wheeler. By the time we got to Hana a bracket in the suspension had cracked. And all the while we had rental cars flying, and I do mean flying as in airborne, rattling past us.

 

RI has probably some of the worst roads in the country. It's partly to do with winter weather, but also because RI always takes the cheapest way out when repaving, using the bare minimum DOT standard for asphalt thickness(not meant for cold weather areas). All it takes is a couple of snow storms and the frost heave works it's magic as the snow plows lift out anywhere from dinner plate to manhole size cow patties of asphalt from the road creating thousands of pot holes. It's an obstacle course driving to work each day.

While in nearby Connecticut, they generally use more than the minimum and you can see, and feel, the dramatic difference as you cross the border on one of our many common roads.

 

The reason I keep mine at 50/48 is the speedometer is close to GPS speed: only 1 mph faster or less. With 35/33 it's more than 2 mph faster: I don't want to put more miles in the car.

 

I don't think that's a good enough reason to beat your suspension to death......and risk being right on the edge of exceeding the safe maximum pressure.

AND....without some detailed testing, you can't be sure that the speedo and the ODO have the same margin of error.

 

I lowered mine to 42f 40r this evening. We'll see how it is over the next few days. I couldn't endure the sound of my teeth chattering on every bump and pothole for the sake of a few mpg!

 

So I dropped mine to 35/32 and my mileage dropped from 56 at 40/38 to 55 so not much difference and a better ride.

 

Its molded on the sidewall of every tire along with brand and size.
The higher pressure on a 175 section tire doesn't affect the tread wear as it does for wider tires.

 

I started with the 36fr/32rr from the dealer - just over 5500 miles and am trying 40fr/36rr for a.but but it seems bit stiff - time will tell.

 

I find it depends on the tires.

Skylis 1 had tires rated for a maximum of 44 psi. When I rose the tire pressure to 42 psi, the ride was stiff and I had to use the brakes a lot more because the car would just keep going.

With Skylis 2, my tires are rated for a maximum of 51 psi. But even though I still use 42 psi... the ride in Skylis 2 is super smooth and there is a slight bit more drag when I let off the pedal, compared to Skylis 1.

 

This made me close this thread. I was interested in better MPG's at the cost of comfort. But, I am planning on keeping this car LOOOOOONNNNNGGG time! So I guess I won't mess with them. Manufacture's suggested pressure all the way!!

 

40 psig both front and rear seem to be best for ourhybrid customers, however, running the max air pressure of 51 psig is running a bit close to being a problem if you hit a pothole at speed. And we haven't found any benefit running over 45 psig. none whatever.

 

Tried 42/40 and down to 32 F&R.

38.5 to 39 F&R is right for me.

Under my driving conditions - MPGs don't seem to get much better at higher pressures.

Even at 36 F&R - I average right around 50 MPG - but 38 to 39 seems the best for me.

YMMV

 

I keep mine at 42 F&R, still on stock tires at 36,000 miles. They are needing to almost be replaced. I did close to 1200 miles traveling between cities at speeds over 80, and sometimes 90. So the tread was abused a little bit. I average right around 47MPG with my highway and city driving. That usually translates into about 400~ miles on a tank.

 

I am Bill, but the picture is my wife. Anyway, yes you can improve mpg by raising tire pressures, but have to remember that interstate driving will raise the heat and thereby the tire pressures and lower the life of your tires. Check pressures as soon as you exit the interstate and make sure you have a safety margin below maximum allowable pressure. For in town only driving you probably can get away with higher pressures if you can stand the extra roughness. Personally, that is one thing we did when much younger, but now we just use the factory recommended pressures as the best compromise for real world variable conditions that are out there like driving 75 mph in New Mexico and Az.

 

i am 40psi on all 4 tires. the suspension and response at 40psi is crisp yet compliant. i like it.

 

The Maui road to Hana is pretty bad. We got semi run off the road twice, coming back, by oncoming vehicles cutting over the centerline. One was some sort of flatbed carrying a vehicle. The other was a cop in a SUV! Luckily in both instances the shoulder was level enough that we could run off, avoid a head-on.

 

Welcome Bill.....and wife.

The MAX. pressure on the sidewall is also a COLD reading.

I don't think that max. hot pressure limits are an easy thing to find, if they even exist.

 

ChuggyPig handles well with 42f and 40r, and is returning 48-55mpg around here (NE USA)

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