Tire Pressure / Mileage / Maintenance

[Svashtar]

Just finished my first week with the new MM. Filled up with my first tank of gas and calculated a very disapointing 15.5 mpg, and of course this is all stock. Thought maybe it was the way I was driving it in town, so made sure I was not sitting idling for long, etc., etc., and thought maybe it was because I had not driven my "normal" number of freeway miles. Anyway, at $46 a tank I was concerned, as the dealer had supposedly delivered it to me all set to go with no problems.

Today after washing it I thought I would check the tires and found the problem! (Or at least what I HOPE and assume to be the problem.) Both front tires had 20 lbs of air. The rears had 22 and 25 respectively. I could not believe that I hadn't noticed it but the profiles look so low even at the correct pressure that I couldn't tell by eyeballing it, and frankly I don't think I should have had to after paying cash on the barrelhead for a new car that the dealer is supposed to have checked out for me. Yes, it's an '03 and has been on the lot 20 months but so what? The car was supposedly checked out and detailed top to bottom, but as I mentioned on another thread I had to take it back after 5 days to get the watery oil changed as it had condensation in it from sitting so long.

I have no idea what damage I might have done to these things driving them that underinflated for 300 miles, but Monday I am telling the dealer that if one weird thing goes wrong with these tires then he is buying me a new set. What an idiot...!:shake::mad2:

Finally, I had wondered why the tires seemed so dull looking and had almost zero markings on them. Today, after inflating them, I leaned on one and was surprised that my hand came away just filthy. This is after washing the tires. I started rubbing them with clean towels and TWO hours later I finally got them scrubbed and clean and got all this incredibly stickly goo off of them, and can actually see the letters on the sides of the tires. I know they don't come that way from the factory. The only thing I can figure is that every day or two when they hose the cars down they probably shoot the tires with armor-all, and someone was too damned lazy to wipe it off. Over a year and a half of armor all or some similar junk coated those tires, and it was one big PITA to clean up believe me!

I have a wheel cleaner that takes care of brake dust etc., on the rims, but thought that plain old car wash would suffice for the tire sidewalls. Guess not.

Anyway, enough *****ing! Any thoughts on how the tires might handle being run that low for a week would be welcome.

BTW, the fuel door says 32 PSI all around, whereas I heard the '04's say 35 PSI. Same tires both years right? Did LM figure 35 was better in the second year? Let me know what you think is best. Mine is one of those 300B's with all the 300A features plus the traction control.

Thanks as always for your input!

Regards,

Norm

[Donny Carlson]

Your tires may have oxidised somewhat for sitting so long in the weather, which may explain some of the black you got off the tires. If the car sat for a long time in one spot, you may have a flat spot on each tire that should work its way out after a couple thousand miles. If not, you should have them replaced under warrantee. I don't think your driving on slightly underinflated tires damaged them. Keeping your tires inflated properly will help your mileage, but also your mileage will get better once your engine loosens up a little. Your car is still "green" and very tight, which will cause mileage to suffer at first. You may want to consider going to an oil like Royal Purple for yor first oil change, then stick with it, and enjoy a mileage boost from the goodness that is Royal Purple.

[Svashtar]

Your tires may have oxidised somewhat for sitting so long in the weather, which may explain some of the black you got off the tires. If the car sat for a long time in one spot, you may have a flat spot on each tire that should work its way out after a couple thousand miles. If not, you should have them replaced under warrantee. I don't think your driving on slightly underinflated tires damaged them. Keeping your tires inflated properly will help your mileage, but also your mileage will get better once your engine loosens up a little. Your car is still "green" and very tight, which will cause mileage to suffer at first. You may want to consider going to an oil like Royal Purple for yor first oil change, then stick with it, and enjoy a mileage boost from the goodness that is Royal Purple. Thanks Donny. I was going to go with a pure synthetic like Mobil 1; is Royal Purple similar? Thanks for any information.

I don't think there were any flats on the tires; the car had 300 miles on it, the dealer insists its from being delivered and test driven. It seemed like a lot to me, but it was so apparently clean I didn't worry about it. The tire stuff was more than oxidation; it was a thick, viscous layer of pure gooey gunk that was a total pain to get off. I spent an easy 30 minutes per tire.

I would be more than happy with 20 MPG, and know that should be doable.

Hey, anyone, any info on the PSI? 32 or 35? and do you know why LM switched from 32 PSI in '03 to 35 in '04 as I heard?

Thanks again,

Norm

[67435animal]

Thanks Donny. I was going to go with a pure synthetic like Mobil 1; is Royal Purple similar? Thanks for any information.

I don't think there were any flats on the tires; the car had 300 miles on it, the dealer insists its from being delivered and test driven. It seemed like a lot to me, but it was so apparently clean I didn't worry about it. The tire stuff was more than oxidation; it was a thick, viscous layer of pure gooey gunk that was a total pain to get off. I spent an easy 30 minutes per tire.

I would be more than happy with 20 MPG, and know that should be doable.

Hey, anyone, any info on the PSI? 32 or 35? and do you know why LM switched from 32 PSI in '03 to 35 in '04 as I heard?

Thanks again,

Norm

I run my fronts at 32 and my rears at 40.

Bob

[Marauderjack]

35 front and 40-42 rears.......The rears will wear out in the center if under inflated!!! :confused: There has been a lot of discussion on tire wear and inflation....check the old posts andmake your own decisions. ;)

My rears were almost gone in the center and bumping them up to 42 PSI virtually stopped the center wear!! :rock:

Good Luck & Enjoy!!

Marauderjack :D

[Svashtar]

Figures the subject would have already come up here! Should have checked but figured everyone would just follow the gas door inflation #'s. Thanks for the good information!

Norm

[Bluerauder]

35 front and 40-42 rears.......The rears will wear out in the center if under inflated!!! :confused: There has been a lot of discussion on tire wear and inflation....check the old posts andmake your own decisions. ;)

My rears were almost gone in the center and bumping them up to 42 PSI virtually stopped the center wear!! :rock:

Good Luck & Enjoy!!

Marauderjack :D
I am running 35 PSI all around and getting 23 mpg on the highway. Only about 18-19 mpg around town. Will have to check the rears to see if I am getting more center wear. Seems to me that higher PSI would "increase" center wear. :confused:

[SergntMac]

You're on the right track with both topics, Norm. I run with 36 PSI in all corners, and my highway MPG is well above 22. However, some would say the ride suffers and they can feel too much highway. Track your PSI, see what works for you. Sure sounds like a build up of tire dressing, maybe once a month, I pull the wheels and coat the tires with Goo Gone. While that's working it's magic, I wash our the insides of the wheels. Works for me.

[Marauderjack]

tstrat....

We have beat this one to death and I know from experience that 26 PSI in the rears accelerates center wear tremendously!! :o It seems the rear tires are slightly large for our rims causing the center to bulge slightly while the fronts are slightly small causing the edges to bulge slightly??

By upping the PSI in the rears I can see the centers becoming concave thus throwing more wear to the edges?? :confused: I guess the belt under the tread only allows it to expand so much and the stiffer sidewalls push the edges out?? :confused:

May not follow the accepted knowledge of over/under inflation and wear patterns but the truth is it works for me and I'll get 45-50 K miles on the fronts while my new rears will probably go 30+K miles (the originals went about 8K miles).......I'll keep ya posted!! :rasta:

Marauderjack :pimp:

[67435animal]

I am running 35 PSI all around and getting 23 mpg on the highway. Only about 18-19 mpg around town. Will have to check the rears to see if I am getting more center wear. Seems to me that higher PSI would "increase" center wear. :confused:

It seems that lower rear pressures cause the sidewall to flex which causes the center to wear (at least this is what I was told); so far I have zero center wear after almost 6K on my second set of tires.

Bob

[Marauderjack]

Same here Bob......5K miles and they still look new!!! :rock:

Marauderjack :rasta: