The max pressure is for 'cold', that is undriven, tires not loaded in excess of the max load rating.

 

Just spent hours dealing w/ this pressure thing. Last night the low pressure light came on and today I did a test - less than 25 psi on all 4 of them! I am so mad, because I drove less than 200 miles out of the dealer lot and obviously the dealer didn't fill up enough air. Anyway I drove to the nearby Walmart to buy an air compressor - thinking that it would be a good idea to keep one in the car. The little cheapo thingy either didn't work or wouldn't work for me. After making a lot of noises I couldn't get the pressure needle to move up. So, I got rid of it and went the gas station next to it, and filled up the air w/ a few quaters. So much easier! On my way back home the warning light went away although the ride felt a lot stiffer (don't like it but will live w/ it). Now I have 33 psi on all 4 tires.

Does anyone know a good electric air compressor that's very compact and actually WORKS (I mean, w/o taking half an hour to fill up a tire)?

 

Thank you, sir. I stand corrected.
However, it is nonetheless not to be used to set inflation pressure as a tire can be used in a variety of applications.

 

Amazon.com: Master Flow MF-1040 Cyclone High Volume Portable Air Compressor: Automotive

 

setting your tires to "tire PSI"? oh brother.........

 

I don't know everything. There are some other sharp folks here! I guess I'm a little over-obsessed with tire pressures after running 295/30 R-compounds. There is not much rollover of the tread (nor sidewall) on those. Despite what Mr. Officer says, tire pressure is absolutely the name of the game--along with alignment (and suspension geometry). The exact tire pressures needed vary quite a lot from one tire's construction to another and for different things you might be trying to achieve/tradeoff. The lower the profile and the wider the tire, the more the contact patch changes from a long strip to a wide patch, and it becomes a huge challenge to keep that wide patch properly loaded and in contact with the road. Luckily, my Fit isn't as finicky.



This is a "foot print" of my 285/30. Interesting how you can see the shape, load distribution, camber, etc. Well, OK, at least interesting to me.

 

There's alot more about tires than people think. I went to a 4 hour training seminar and 2 hours of it was just tires. The other half was primarily on oil alone!

 

Does anyone know a good electric air compressor that's very compact and actually WORKS (I mean, w/o taking half an hour to fill up a tire)?[/quote]

There are several air compressors available at sears, walmart, etc.

One is 120vac that we move around the shop and came from sears. The other is probably what you want; it's a 250 psi rated 12vdc powered unit. It inflates a Fit tire in a few minutes at the track. The key its getting one with at least 150psi capability and preferrably 250 like ours. sorry, there's no brand on it but I think we got it at WallyWorld. Neither of these cost more than 40 bucks as I remember.

You need to have a good tire pressure gage and check your psi on 'cold' tires (ones not driven for a couple of hours and not in sunlight.
35 psi is a good starting pressure. Naturally the higher the pressure the harder the tire so your ride deteriorates proportionally.
If you were particularly vocal about a 'smooth' ride the dealer may have set tire pressures just at the sensor setting and your driving set TPMS off because the pressure was so low.
Checkyour tire pressures weekly anyway.

 

The people that did my 4-wheel alignment (yeah, I know, you can only set the front toe-I just like to know that ALL the wheels are pointing in the same direction) set my TP to 45 psi from 36 psi. They said there was some feathering on the outside edges. I'm running Toyo Proxes FZ4 205/45-16's on HFP wheels and didn't notice any increase in harshness, but there was an improvement in handling. The tires have over 20K miles at this pressure and are 5/32 inch tread depth across the tread.

 

Oops, forgot this was the 2009 section. The 20K miles is on a 2008 Sport, the 2009 is supposed to be delivered tomorrow! I also used a tire pyrometer, but I don't think I got the tires hot enough, even driving hard in the N Ga mountains. The pyrometer is for Road Atlanta-not that the Fit will ever get on that road.

 

So how about telling us the alignment data? Caster, camber, and toe on all 4 wheels. Didn't get that? Hmmm.
And how about the offset on your wheels?
Thanks. Just trying to feather the database.

PS 45 psi will improve handling but you may see an increase in tire wear in the center of the tread.

 

All numbers are in degrees, numbers in parens are the "before" readings
Frt: lft Frt: Rt
Camber 0.1 (0.1) -0.3 (-0.3)
Caster 3.7 (3.7) 3.9 (3.9)
Toe 0.00 (0.01) -0.01 (0.07)
Front
Cross camber 0.4 (0.4)
Cross caster -0.2 (-0.2)
Total toe -0.02 (0.09)
Rear: lft Rear: Rt
Camber -1.5 (-1.5) -2.1 (-2.1)
Toe 0.06 (0.07) 0.06 (0.08)
Rear
Total Toe 0.13 (0.15)
Thrust angle 0.00 (-0.01)

I couldn't beg the dealer to check the alignment (9,059 miles), they drove it and didn't see a problem driving around the block, but on the Interstate it just wasn't right, the alignment fixed that.
I'm letting Honda decide the proper offset of their High Performance wheels.
And what part of 5/32" across the the tread do you not understand? Thats half the tread after 20,000 miles, perfectly even wear...
I suppose I could take the car to a frame shop and have it bent so every measurement is in the center of the specified range, but I'll just settle for the 0.00 thrust angle. BTW, The four wheel alignment I did on my Ranger with 30K miles transformed the way it drove. Consider the database feathered.

 

Great alignment tangent since Fit alignment is new to me.

Tire construction can vary quite a lot including the amount of "crown" in the tread surface. I would have guessed 45psi would have lead to excessive center tread wear, so I'm glad your Toyo combo working out for you. Seems like you are paying attention (tread wear, tire temps, alignment)

 

I would say they only corrected the right front toe. Nothing else changed. The camber, caster, and toe were pretty good to begin with as the dealer noted although changing the right front toe to near zero is an improvement. Probably only a 1/16th inch change, maybe 3/32" (1.5 to 2 mm).
And the even wear is substantiated by the 'before' measurements. Lots of cars aren't that good. One of the things I really like about your alignment is the static camber. When you sit in the car your front camber probably evens out at about -.2 deg, which will be a nice handler with the rear setup. I guess the Honda wheels are 53 to 55 mm offset from tha camber readings. (its cast in back of one of the spokes)
And I wouldn't take it anywhere to change anything. Its better than 90% of the cars on the road.