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New tires?

Discussion in 'Wheels & Tires' started by NelliM60, Sep 30, 2016.

  1. NelliM60

    NelliM60 Member

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    I wanted to change my tires but only had 2 new ones at the time. Also I didn't know they were LT type rather than P type and were 75s rather than 70. The mechanic brought it to my attention and informed I couldn't have 2 different type and size tires on a 4WD, though I drive my truck at 2Hi most of the time (rarely do I use AWD option, and even far less have ever used the 4Hi or 4Lo options). I ended up buying 2 tires from him and since I wanted to upgrade, I bought the same new type and size. (So I went from P245/70r16 which are OE demand, to upgraded LT245/75r16, but different brands. Goodyear Wrangler brand on the fronts, Grenlander L-finder brand on the rears).

    Issue?: Twice my rear tires slid on wet pavement turning left/right while decelerating. Several times now, the front tires (passenger side, I strongly believe) spins out on wet pavement during take off acceleration at a curve, when cornering, even at a straight take off, and I don't speed off. If it helps I did not have the tires undergo a wheel alignment or rotation yet. So I believe that even a dumb question is just as important which is why I'm posting this. What is happening to my Street Queen? Is the truck affected by the new type and size of the tires? Or by the mixed brands? Or am I overreacting on an issue that simply can be resolved by alignment/rotation service?
    Thanks Guys.
     
  2. Wooluf1952

    Wooluf1952 Well-Known Member

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    You say you only use 2HI? But you believe the front tires are spinning even in straight line accelerating? Something doesn't add up. If you're in 4AWD or 4HI. and the front tires spin even at low power acceleration, you might try checking the air pressure in the tires. :undecided:
     
    Last edited: Oct 1, 2016
  3. djthumper

    djthumper Administrator

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    Admin Post
    Your ABS is out of sync due to having 2 different sized tires. This is why you cannot run 2 different sized tires.
     
  4. Chickenhawk

    Chickenhawk Well-Known Member

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    Here is my opinion. You are not going to like it. Brutally honest is my middle name. (My mother hated me.)

    You made the right decision to buy four tires the same size. The problem is the tires. This is why I suspect you will not improve them much with an alignment unless your wheel alignment suddenly went WAY out.

    Those Grenlander tires are no-name tires made in China by the Shandong Laongyue rubber company. (I am sure you can tell by the horrendous smell from the Chinese-made rubber!) They make hundreds of different discount tires under a variety of different names, all spelled in ways to mislead consumers into thinking they are some kind of European-made tire. They are not. They are cheap Chinese junk.

    Sadly, the name brand Goodyear Wrangler tires are not much better. They are rated very poorly on our platform and many drivers with Blazers and Trailblazers got rid of them as soon as they wore (often prematurely.) I have always found them to be an exceptionally slippery tire, and tend to wear off the edges quickly because of their excess tire slip.

    Plus, unless you carry VERY heavy loads or routinely pull a heavy trailer, you are killing your ride by going from a P-rated tire to an LT-rated tire. The sidewalls in the LT tire are MUCH stiffer.

    A lot of tire dealers will try to sell us on LT tires because they either have them in stock or get better profit margins on them. We drive a light truck, but we do not need LT tires on our platform. If you read the specs and tire sidewalls, you will note that the maximum weight rating of P-rated tires in our size easily exceeds the gross weight rating of our truck with only three tires. (This is important so that if you have a blowout on the highway of one tire, it should not result in a sudden blowout of a second tire.)

    Let's do the numbers. P-rated tires run about 2100 pounds per tire at max inflation pressures. Our vehicles weight about 4400 to 4600 pounds, and gross vehicle weight ratings run around 5400 to 5700 pounds. Three P-rated tires at max inflation hold up to 6300 pounds. This is why I recommend not letting a dealer sell you on LT tires on a street vehicle unless you need the extra load capacity. (LT tires are around 3100 pounds at max inflation, which are far more than most drivers will ever need on our platform.)

    You are also going to lose dry traction by going to a narrower tire.

    So your ride and handling have now been compromised by poorer tires, narrower tread width and a weight rating much higher than necessary. In my opinion, I would sell them and replace all four. On our platform, the Firestone Destination seems to have many good reports for a lower cost tire. (It is even cheaper than those Wranglers.)

    If, for some reason you can't do that, then maybe consider running those LT tires at less inflation pressure. Goodyear rates a LT245/75-16 as being able to carry 1700 pounds at 35 PSI and 2000 pounds at 45 PSI. I would never run them at their max inflation of 80 PSI. Try 45, and if the ride is better, go down to 40. (I would go no lower than 40 PSI.)
     
  5. NelliM60

    NelliM60 Member

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    Re: Chickenhawk
    You are right, I really did not like the answer, but I can't help appreciating you giving it to me. I really wanted bigger tires because I thought my truck sat lower than most same models that I see and I also thought LT tires were more fitting since we are driving a basic light truck vehicle.
    I knew the Grenlander tires were cheap since I only paid $99 per tire, but didn't know they were inferior Chinese product (and yes, I have smelled that horrible smell when I come to a red light; I actually bought a fire extinguisher because I thought something foreign was burning, no pun intended).
    The brakes are a bit of a problem, but only because I need to replace the rear discs asap because they are at their last wits-end. That is scheduled for tomorrow. Other than that, I'm stuck with these LT tires for awhile. Funny, when I got the truck, she was running on Firestone Destination tires and they really are great tires for that vehicle. I will invest to get those again, but my final question is: can I get bigger tires, like from 16's to 18's without compromising or having to alter anything to get them fitted? Thanks for all your help. Brutal honesty truly is the best policy.
     
  6. Chickenhawk

    Chickenhawk Well-Known Member

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    You can always change your wheel size without affecting anything. You just need to match the overall diameter of the tire. There are many websites that will tell you the size to run. You plug in your stock tire size from your door sticker and it will convert to 17, 18 and 20-inch wheels.

    It's when you increase the overall diameter of the tire that you can run into problems. Your speedometer will be off and it can affect the ABS brake system if you go too extreme.

    However, an increase in diameter of around 5% shouldn't affect much. So check out the various sizes, and look for the overall diameter figures.

    If you want to go much taller than a 5% increase in diameter, it may require reprogramming of your computer and, in extreme cases, spacers to clear your ball joint. However, I will leave that question up to those members of the forum who have far more experience in larger diameter tires than I do. (I run stock sizes: 16s in winter and 17s in summer.)

    If your truck seems lower than others, it may have been modified, or it may simply be that the springs have sagged a bit over the years, too.
     
  7. NelliM60

    NelliM60 Member

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    Re: Chickenhawk
    Thanks for your advice. Humbly appreciated.
     

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