Tire pressure confusion

Do whatever the hell you like.

 

That is pretty much what I am getting out of this thread.

 

I hear you, no one wants to be caught driving with green caps.

 

Relative difference in pressure is needed in order to ensure your front wheels are on the front, in all kind of slippery situations. Same as putting new tires on the REAR axle. You want to have a higher traction on the back, otherwise your rear wheels might end up facing forward during sharp turns.

As for increasing the pressure over the car manufacturer values - its fine with me as long as you do not exceed maximum tire pressure (indicated on the sidewall)

- Alex

 

I'm not disagreeing here but would like to know if there is evidence to back up the claim that a higher traction on the back is so important and that it will be demonstrably improved by lowering the tire pressure two pounds (5% of 40psi if my rusty math is correct). I think I've read that some people let air out of their tires to increase traction on ice or snow. In a front engine car there is more weight in the front (plus at least a driver) so those tires bear more weight. Could that be just as much the reason for more pressure being needed in front? Just curious.

 

Tech 101 – Adjusting tire pressure | Hemmings Daily
Says it is that front wheel drive has more weight on front, so you want more pressure in front. Old VWs would have higher pressure in rear.

 

Yes absolutely. The lower pressure in the rear creates a better "tread profile"; that is, more of the tread contacts the pavement.
BUT......
That probably only applies when the recommended pressures are used.
IF you jack both readings up by 5 lbs or more, the ideal tread profile likely is out the window and maintaining that difference is largely meaningless.

But often in discussions like this facts take a back seat to "what makes you feel good".......
so if it makes you feel good to jack your tire pressures way up, by all means do that.
Same for maintaining the 2 lb offset.

 

There are some aspects of vehicle operation that are so ritualistic with some owners that I don't even bother debating them.

Oil Changes-frequency and type of oil/additives.
Gasoline-benefits of Top Tier vs. anything else.
and
Tire Pressure.

People do what they do in these cases, and they usually are happy with their perceived results, and then nothing anyone says to the contrary or opposite is going to change their mind. They have their ritual...and they are happy with it.

And usually, it doesn't really matter too much...one way or another.

So all I usually say, is what ritual I've embraced...right or wrong.

When I first got my Prius I experimented a with a modest degree of inflation above the Toyota recommended PSI. 3-5 psi max above the recommendation for front and back. But now? I just inflate the tires and try to maintain at what Toyota recommends.

And all I'll say is when I lowered the PSI back down to the recommendation? My MPG did not suddenly crash. I honestly think the MPG are about the same.

BUT...I can say for sure my ride got smoother.

So I don't mess with higher PSI anymore.

But if you perceive a benefit...if that's your ritual? As long as you are being "safe" about it? Do what you want. The only recommendation I would argue against, would be any recommendation that grossly exceeds the tires suggested max. Any benefit real or imagined is not worth risking your safety.

Therefore, I just go with what the sticker in the door jam says. MPG good, and the ride is good.

 

When I got my gen2 last year and after reading here I had my 15" winters up at 44/42 and had to lower them as my teeth were chattering as I drove!

I have summers back on and pressures at 42/40 and it's fine. Might drop them a little more for increased comfort.

 

Yes a high pressure definitely wears out suspension faster. After 200K on the 05 much of that on a rugged rural mail route usually running about 40PSI I had a front strut puke it's oil (strut boots long ago fell apart). Other than hubs no other suspension parts replaced yet. How hard is the driving? No exact count but 7-8 sets of tires so far. (a mix of random all season and Blizzak snows on separate rims) I get about 2 winters and part of a summer out of a pair of Blizzaks. Just now searching for snow wheels and tires for my new to me 2012 v
Probably 8 nail/screw punctures repaired with "from the outside punch in plug strips" with no plug failures so far. Some of those were done on the mail route without removing the wheel from the car.

My main reason for running the higher pressure is (more) even wear, at 30 PSI I chew the corners off in a New York minute.

 

The difference in tire pressure between front and rear is because of the difference in the weight of the front and rear. This makes the tires wear the same. As long as you rotate your tires you can run the same pressure in all tires. I have been driving for over 60 years and have run the same pressure in all 4 tires. The only reason you would put new tires on the rear was if you had rear wheel drive car. With a front wheel drive car you put new tires on the front for better traction starting out and cornering in slippery conditions.

 

Many tire shops disagree, and will refuse to put two new tires on front. They will install them on the rear only, and you will have to swap them to the front yourself.

I avoid the front-vs-rear debate by keeping my tires fairly evenly worn, and replacing all four at once. This is more important on older cars lacking ABS and stability control, where emergency braking with asymmetric traction is more likely to spin the car around. Yes, my household still has one of them.

 

I to replace all 4 tires at once and rotate every 5000 miles so they wear evenly. Before moving to Texas 18 years ago I lived in Erie, Pa in the snow belt. I always found that it was a lot harder to start out in the snow without having the tires with more tread or snow tires on the front with a front wheel drive car. Also harder to get around the corners.

 

I read/heard somewhere that the different tire pressures in front/rear actually affect the alignment on the front end. Not sure but I guess it makes sense if the angle of the car is changing.