Proposed tire rotation scheme?

Discussion in 'Clarity' started by Fast Eddie B, Sep 6, 2019.

  1. Edd

    Edd New Member

    So you don't x out the tires? I thought that was what had to be done. be much easier to do front to rear is thats all it takes.

    So youve done this before and no issue?
     
  2. craze1cars

    craze1cars Well-Known Member

    Correct. And for 25 years as a field based employee I drove cars for a living....between 60k and 90k miles a year. I burned up a LOT of cars and a lot of tires in my care. And I did all maintenance and repairs on every car myself.

    I can’t recall ever replacing a set of tires before 60k, and many sets went well past 80k. Just leave the left side on the left, right side on the right. Trade them every 7k to 10k or so. And manually check tire pressure every 2 weeks. Without exception. This is critical to long tire life. Never trust the on board tire pressure systems. Not accurate enough on most cars.

    And never waste money on an alignment for any car that is wearing tires evenly. They’ll just screw it up most of the time....keep the good alignment you already have. Only get an alignment if you notice uneven tire wear that is not caused by failure to maintain tire pressure. And rebalancing tires is also a waste. They get balanced once at install and never need it again unless a weight gets knocked off.
     
    Last edited: Sep 19, 2019
    2002 likes this.
  3. ClarityBill

    ClarityBill Active Member

    My OEM tires only made 30K, but the wear was the center of each tire - overpressure. I thought I was maintaining at 36 psi, but something was not right...
     
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  4. su_A_ve

    su_A_ve Active Member

    Did you check the tire pressure at delivery? Many had the tires over inflated by the dealers...
     
  5. ClarityBill

    ClarityBill Active Member

    My dealer had dropped the pressure down to 32, and had to raise it up to 36 before I took the car... I checked it every 3000 miles with my cheapo tire gauge.
     
  6. craze1cars

    craze1cars Well-Known Member

    A lot has to do with typical load in the car also. Heavily loaded cars need more air pressure than lightly loaded cars. The door jamb recommendation is really just an average, and the true ideal pressure may vary for various cars and usages. Someone who usually drives empty with driver only may get by with lower air pressure than the jamb says, and if you blindly follow the jamb you may see an overinflation wear pattern. Whereas a car that is usually driven with 4 people and a trunk load of junk may need a few pounds more than the jamb says to prevent shoulder wear. Extensive high speed highway driving usually requires different pressures than urban stop and go driving for maximum tire life. Lots of turns and running around town will wear tires much faster than an interstate car. And some parts of the country have much more abrasive aggregates in their roadways than others due to the type of stuff that comes out of the local gravel pits, which can make a huge difference in tire life. Concrete usually eats tires faster than asphalt. But if you live near steel mills your asphalt may have steel slag mixed in, and that can be VERY hard on tires.

    Anyway this is why I measure my tire tread depth at each rotation, and may change my air pressure accordingly. 3 measurements on each tire...one at each shoulder and one dead center. A tire that is wearing more in the center than at each shoulder is overinflated for my usage. So if the door jamb says 36 I might go down to 32 for a while and see how things balance out. Vice versa if shoulders are wearing faster than center. And if inside shoulder is wearing more than outside shoulder, or vice versa? Or if featheredging is noticed? These issues mean you need an alignment and this has nothing to do with tire pressures.

    The 36 on the jamb tag of the Clarity seems a touch stout for my usage but it is very close. I'm usually keeping them at 34 to 35...usually 1 average sized person in car, no luggage, mixed driving. For heavily loaded vacations of extensive high speed interstate I'll crank it up to about 37 or 38, then let air out to back it down to 35 after I return.

    My last Accord I always had to run it about 3 PSI higher than the jamb for even wear. Same for my truck... about 4 PSI higher than the jamb says. When I put a heavy trailer on it and load up the bed for a long vacation I might go 10 psi higher than jamb on back tires only. My Mazda likes about 2 psi higher than jamb.

    Temp swings make a considerable difference. This is why I check it every 2 weeks. Mileage is irrelevant. As winter approaches you must add air. As summer approaches you must let air out. And if you check/set your tire pressures on an 80 degree day and usually drive during the 50 degree nights because you work night shift, you're consistently under inflated by about 3 to 4 pounds.

    The door jamb is not always exactly right. But it's usually close and if you don't want to get too awful scientific about it, use that number but make sure they are checked when the tire temp is about the average air temp of when you're driving. Don't check them when the sun has been baking one side of the car and not the other, or immediately after a long drive...your numbers will be wrong.

    Buddy of mine worked at a Chevy dealer as a service tech. He often talks about a couple many years ago who purchased a brand new custom conversion van and kept wearing out the front tires super fast and uneven. They kept coming back for new front tires every 10K and making warranty claims to get it fixed because alignment was clearly messed up. However alignment was checked several times and found within spec and pressures good, but front tires just would get chewed up super fast. Well...it turns out this van was owned by some rather heavy people. Husband and wife each tipped the scale near 350 pounds and they always traveled together, each sitting in a captains chair up front above each front tire. Once the savvy alignment tech learned this important detail from the service adviser, he brought the van in and drove it up on the alignment rack, and then piled up 600 pounds of concrete bags on the front floorboards and seats from the local hardware store. THEN, with this load in place and front suspension notably squatted down, he changed alignment to Chevy spec. He also bumped up air pressure on front tires up by about 8 PSI and they carefully marked the customer's files with these new specs for future reference. With this combination, problem was largely solved. The factory specs and recommendations simply did not work for this couple's van, because the two of them were far too heavy for those specs to work correctly. My friend also was building a deck at the time so the concrete was put to good use after the alignment was completed...

    This became a long essay but summary is this: If you monitor your tire wear carefully by taking tread depth measurements at each rotation, and make minor permanent pressure adjustments, or even alignment adjustments, based on the wear patterns you start to see, you can definitely make your current and future sets of tires last longer. If you don't want to bother with it, that's fine, you'll just have to buy new tires maybe 10K miles sooner than I will....
     
    Last edited: Sep 19, 2019
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  7. insightman

    insightman Well-Known Member

    @craze1cars, you make this great forum even more informative and interesting. Thanks!
     
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  8. Landshark

    Landshark Active Member

    There certainly has been a meal made out of the tire rotation subject. Mine rotate when I drive.

    So far we have almost every possible rotation scenario except, don’t bother rotating them at all, and everyone is sure their method is best. Some kind of rotation protocol is better than none. I’d suggest following the guidance in the manual.

    If that is beyond ones capabilities, take the car to a tire shop. They may rotate the tires at no charge, maybe $20. Either way you won’t break a sweat, twist the frame or risk your life.

    Parking brake can be simple or complicated. I choose simple. Stop car, press P, pull up on Parking brake switch. Brake is on.

    Tire pressure is simple as well. The 36PSI on the door jamb is not an average. It is the recommended “minimum” pressure to support the GVWR of the vehicle. That weight is approximately 4800 lbs. Car 4000, passengers and cargo, 800.

    If you do not have access to an inflation chart do this math. Tire wall max load divided by tire tire wall max pressure.
    1477/44= 33.6. This gives you a load, in lbs, that each PSI will support.
    33.6x36psi=1208. Times 4 tires is 4832.

    If you and your tool kit and briefcase weigh 200lbs, you could theoretically run 32psi. If you take 2 coworkers to lunch or pick up the kids after school, you should stop and add 2-3 lbs first. Then let’s some out when you’re done, if you can really notice a difference in ride quality from 36 to 34.

    Again, the recommended pressure is the “minimum” pressure required to support a given load. Under inflated tires are more likely to suffer premature wear and failure than over inflated tires. I’m talking a few lbs. I run mine at 38-39, for 1-4 people, check cold pressure monthly and don’t adjust for temperature variations throughout the day.
     
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  9. 2002

    2002 Well-Known Member

    If a car is on a lift it's just as easy to cross rotate as not, so it's not surprising that this is what the manual recommends since there could in theory be a slight benefit in some cases. When doing DIY rotation however it takes extra time and additional lifts to cross rotate. So following the guidance in the manual could be adding additional work that has little if any benefit, thus the discussion about it. Yes academically it's simpler to say just follow what the manual says, but the discussion here is about DIY. If taking it to the dealer of course have them do what is in the manual, why wouldn't you expect that, even if it's not certain that there is any benefit, they are being paid to do it and for them it's just as easy to cross rotate so that's what they should do.

    For me it's even simpler I just press the power button. That puts it in Park automatically. And since I always have Brake Hold activated it also automatically sets the parking brake.

    Recommended tire pressure is primarily for safety reasons. Overinflation reduces stopping distance and can affect handling. Underinflation can lead to tire failure which is dangerous if it occurs while driving. Not following the manufacturers recommendation should be done only when you know for sure that you are either making the car more safe or at least as safe, something which in my opinion is not simple.

    It's actually giving you the square inches of footprint. The units are lbs and lbs/in². 1477 lbs / 44 lbs/in² = 33.6 in². 36 lbs/in² x 33.6 in² = 1200 lbs (x 4 = 4,800 lbs)
     
  10. Landshark

    Landshark Active Member

    I tend to not overthink things.

    I also tend to follow the recommendations of companies like Honda and Michelin who have teams of engineers, rather than listen to speculation, unproven theories, anecdotal evidence or just plain nonsense about tire pressure.

    The OP asked for thoughts about a proposed method for rotating tires. I suggested following the recommendation in the manual. It isn’t that difficult.
     
  11. As an update, we just hit 30,000 miles on our 2018 Clarity, and I just finished our third tire rotation.

    For those paying attention, this time was front-to-rear.

    I’ve always tried to keep tire pressures at 36 psi, and I think that’s resulted in pretty even wear so far:

    [​IMG]

    If all goes well, I’m hoping for at least 40,000 miles and, hopefully, one more rotation.

    Wish me luck!
     
    insightman likes this.

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