Air Pressure and Torque

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Old 11-22-2017, 05:58 AM
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Air Pressure and Torque

Noted on the door jamb - 42 lbs for the fronts and 39 lbs for
the rears. Still scratching my head when I realized that the
dealer had between 47 and 48 lbs in all four tires.

On a separate note, what do you guys torque the wheels at?
 
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Old 11-22-2017, 06:06 AM
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Read your manual

My manual says 101ft-lb for lugs.

For air pressure it's not uncommon for dealers to do that, no idea why, just careless I guess. Or, did you measure when the tires were still hot?
 

Last edited by trentiles; 11-22-2017 at 06:11 AM.
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Old 11-22-2017, 06:17 AM
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Don't have my manual handy but somewhere
I believe I saw convertibles were about 103 ft. lbs,
whereas the hatch was 101. Will eventually get to
my actual manual to confirm.
 
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Old 11-22-2017, 06:41 AM
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Originally Posted by ridgemanron
Don't have my manual handy but somewhere
I believe I saw convertibles were about 103 ft. lbs,
whereas the hatch was 101. Will eventually get to
my actual manual to confirm.
Here's your owner manual for a vert: http://www.miniusa.com/content/dam/m...s/MY17/F57.pdf

Page 208 says 101ft-lb. It was 103 for gen 2's, but seems like it's just 101 across the board now for F56/F55/F57
 
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Old 11-22-2017, 07:22 AM
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thanks
 
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Old 11-28-2017, 11:45 AM
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Those 2 lb-ft of torque value difference are well within the +/-4% most torque wrenches have for a tolerance, so I wouldn't worry too much about that differential.

As for you tire pressure, set to match the door sticker first thing in the morning, when tire/air temps are likely the coolest. I typically run my tires ~3 psi above sticker readings to keep rolling resistance down and boost my MPG a little. I have never noticed any negative wear on the tires running a slightly higher pressure, FWIW. YMMV
 
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Old 11-28-2017, 11:52 AM
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Thanks for your input.
 
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Old 11-28-2017, 01:09 PM
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2nd gen here.. I cant run recommended air pressure .. its far too high for a tiny/light car. Ive set 34 in the front and 32 in the rear.. which seems to be just enough PSI to keep my sensors from tripping. Ride quality is vastly improved vs. the 'over inflated pressure' recommended by the sticker and dealer. I didnt lose any mpg and there is no sag/droop in the sidewall at all either.

*IMO - a high wear pattern in the center of your tire typically indicates too much air pressure, causing a 'rounding' of the tread block.. wear pattern at the outer edges of the tread block typically indicates too little pressure, causing the tread to flatten and roll over the sidewall on turns.

Different tread patterns and speed ratings will tolerate changing pressure in a variety of ways. So long as your tread is wearing evenly, the PSI is "good enough" .. I think the rest is just driver preference.
 
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Old 11-28-2017, 02:56 PM
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Even with the incorrect 47 - 48 lbs that the dealer set my
tires at when I picked up the car, I didn't experience any
problem. Now, after following the 'door jamb' instructions
of 42 front and 39 rear, I 'again' have experienced no problems.
 




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