I've been a bad bad Prius boy--Tire Pressure

.... go, and sin no more

 

A small "pancake" compressor is not all that expensive. I suggest that you buy one for your garage and set your tire pressures every weekend. You would be surprised how fast they drop when using the elevated pressures recommended here on PriusChat.

 

You would have noticed that had you been religious about setting the pressures weekly or even bi-weekly.

 

I mothballed my compressor and use an old bicycle pump instead. The quiet is nice.

 

I just check mine at the petrol station about every few weeks, I'm rarely down more than 2 or 3 PSI.

On a camping trip recently I had to travel few miles but on very rough rutted dirty roads. I set the tires down to 22 PSI (is that some kind of record) and left them like that for the whole three days I was there. I only drove about 7 miles over that three days and only at about 25 MPH. It didn't seem to hurt anything.

 

Gosh, not to be a stick in the mud but...
I never(of course I check them quarterly) have to make adjustments to my tire pressure when the tires are filled with Nitrogen, and in my Hybrid Highlander and Prius I just wash the in cabin air filter three or four times a year.

 

I checked my tire pressure after reading that dealers lower them to give a smoother ride. Yup tier pressure all around was 30. After I get my car back today I am pumping those babies up.

 

It's the cat and mouse game with tire air pressure at the dealership. Everytime one of my cars goes in ,it comes out with factory tire pressure even when i tell them don't touch the tire pressure.My cross to bear i guess ,for going to the dealership. Foregive me father for i have sinned.

 

Why so low, what do you gain from 22PSI and can that help in snow?

 

I don't know about snow, being here in sunny So Cal. My son goes off road in his Jeep, and lowers the tires all the way around to make it easier getting over rocks, etc. Of course he has special valves that he can set with the desired pressure and an on-board compressor system to pump them back up for highway use.

I like to check my tires every couple of weeks at cold pressure, so I have a portable tank in my garage, which I find quicker to use than a portable compressor. My daughter just bought her first Prius, and the next day we went out and bought her a tank and good quality pressure gauge.

The problem with dealers never goes away. I'm thinking of putting green valve stem covers on next time, just temporarily. Maybe they'll think I have nitrogen in my tires and not just automatically lower the pressure.

 

Mostly for ride comfort on very corrugated dirt roads, but also for traction on some sandy tracks at the camp site.

You have to be careful how low you go. Obviously the tubeless tires need the pressure to seal them to the rims, and you've got to be mindful of not bottoming out the tires. There's also slightly reduced ground clearance, so 22 PSI is about as low I'm prepared to go. And that's with keeping to a very reduced speed.

The track is very corrugated and with hard tires you just bounce and vibrate like crazy. Large 4WD's will typically travel it at about 45 to 50 MPH, but it's an isolated location with very little traffic so it's not really a problem to go much slower. Only one vehicle passed me in the same direction while getting there and back. Like I said it's only about 4 miles (each way) of the rough road, so taking it real easy at about 20 to 25 MPH only adds about 10 minutes to the (3 hour overall) trip.

I'm not sure about snow, but in sand there's a huge improvement in traction with using these very low tire pressures. After the rough road to get into the area, it's then some sandy tracks to get to the best camp sites (it's a coastal area). Here the low tire pressures can really help too.

BTW. I pumped the tires back up to 40/38 as soon as I was back on the main road, and still averaged over 50 MPG for the overall trip.

 

In snow you either need to stay on top of the snow, pack it down solid, or push through it to pavement. You aren't going to stay on top of it with a passenger car on tires, so low pressure doesn't help and probably hurts.

On dirt, gravel, rocks, etc you get better traction when the tire conforms to the surface, so the lowest pressure you can safely run is good.

If your pressure is too high you will sink into sand and pieces of gravel will act like ball bearings if the tire can't encompass them a bit.

 

I had the same problem a month ago. I was actually going to lower my pressure for a more comfortable ride and to my surprise it was already lower thanks to the cold weather. Pretty embarrassing.

 

Didn't you get the tire pressure warning light on the dash?

Only time I got the warning light was when the dealership lowered the pressure for 'courtesy' after a tire rotation.