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Thread: Help me decide new tire width.

  1. #1
    Flashaholic*
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    Default Help me decide new tire width.

    My tires are getting REALLY bald and it's time to replace before the rainy season in San Diego starts up again around April and May.

    First of all I am not an aggrasive driver all the time, but I can get quite spirited from time to time just for the hell of it. Mostly, i'm a conservative driver who follows the speed limit 80 percent of the time. The fastest I would drive is usually 80mph, which seems to be (sadly) the flow of traffic in Southern California. After being involved in and witnessing a HORRIBLE fatal accident (I was not at fault and walked away okay with little to no damage) I am sure to keep my speed down. Losing control of ones car at 40 mph is one thing, but seeing someone lose control of their car at 80mph, up an embankment, flipping end to end....it's a completely different story....

    Anyway, I believe tires are one thing a person shouldn't skimp on a car. My OEM tire size is 195/65/15. I've experimented with different plus sizes from stock 215/60/15 to 205/60/15. At 215/60/15 the steering became noticably harder (a bad thing) and I believe contributed to some of the minor suspension repairs over time. At 205/60/15 the steering was MUCH better, gas mileage improved quite noticably, and overall performance seemed to be better than the OEM size.

    Can anyone tell me the negatives and positives (if any) for choosing 205/60/15 or 195/65/15? All the comments i've read at other forums are too focused on performance and style. I've outgrown all (most) of that but i've become very comfortable with the plus one size.

    My dad changed his truck tires back to factory size (195/65/15) and it was more comfortable to drive and stear than the bigger tires we chose last time; however, I can't tell if it was due to the change in size or the change in brand/tread design.

    Overall the price difference between the two sizes are not too bad. At 205/60/15, each tire costs $100. At 195/65/15, each tire costs $88. After installation, warranty, and taxes we're talking a difference of about $60. Have any of you had any experience in switching tire sizes over the years?

    If I had to pin point my interests in driving it would have to be safety and noise. With both tires keeping the same diameter, all that is changing is tire width. How does tire width in this case affect fuel economy, braking and steering performance, noise, and tire wear?
    -Laurence

  2. #2

    Default Re: Help me decide new tire width.

    The difference between those two sizes is just 10mm in width (0.4") which is so insignificant that it is completely overshadowed by brand and model, which are far more reliable indicators of performance.

    If the two are the same brand and model, the wider tire will tend to have slightly worse fuel efficiency and better stopping/cornering power. It will also offer slightly more protection for the rim from curbing.

    Besides the obvious change in overall width (205mm instead of 195mm) there is a slight change in theoretical height. The 205/60-15 is 24.7" tall (60% of 205 is the height of the sidewall; two sidewalls and 15" for the wheel is 627mm) while 195/65-15 is 25.0" tall. Once you start measuring real-world tires you'll discover that brand has as much to do with actual size as the size stamped on the sidewall (like shoes, some brands are notorious for running large or small).

    A note about performance, especially for a truck: the old Explorer was speced by Ford to have 26psi in the tires despite the hit in fuel economy because the prototype could possibly roll over at 35psi (something we learned during the Firestone tire fiasco). So too much cornering performance could be dangerous with a high center of gravity; something to ponder when you see those SUVs rolling with the bling 22" wheels and high performance tires.

    Noise and tire wear have nothing to do with size and everything to do with tread pattern and construction. I'd suggest the Tire Rack's survey because it is the largest there is that rates noise, performance and wear: http://www.tirerack.com/tires/surveyresults/index.jsp

    Besides tires/alignment, the single largest improvement in handling performance is usually from quality shocks.

  3. #3

    Default Re: Help me decide new tire width.

    An easy way to compare size differences:
    http://www.net-comber.com/tirecalc.html

    You might also want to read up on tire ratings (traction, tread and speed) and then see what suits your needs:
    http://www.safercar.gov/tires/pages/tireratings.cfm

    http://www.discounttire.com/dtcs/inf...Hl!830298!NONE

    http://www.edmunds.com/ownership/tec...9/article.html

  4. #4
    Flashaholic* 3rd_shift's Avatar
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    Default Re: Help me decide new tire width.

    If the old tires wore evenly, it may be best to stay with that same size.
    The oem Michelins on my Dodge sprinter van are now at 85,000+ miles, and still look good for another 5-10k after I did the "penny" tread depth test on them.

    Look for load range specs, and the number of plies in the tread and sidewalls.
    It looks like 4 ply tires should be a reasonable choice.
    2 in the sidewall, + 2 in the tread.
    I have loaded and delivered quite a few name brand tires in your size that are like this.

    If your tires did not wear evenly, where is the most wear happening?

  5. #5
    Flashaholic* 9volt's Avatar
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    Default Re: Help me decide new tire width.

    Quote Originally Posted by LEDagent
    First of all I am not an aggrasive driver all the time, but I can get quite spirited from time to time just for the hell of it.
    You're making this more complicated than it needs to be. If you want your car to grip better in corners get the widest tire that is acceptable for your rim. If you don't care that much about it, get the stock size. Call the tire Rack and they can verify the sizes for you.

    The bigger issue is what kind of tire do you get, and how will it perform in the rain vs dry. An all season tire will work great in all seasons and should give fine performace in the rain. You won't get as much out of it in the dry, but it sounds like that isn't a big deal. You do sacrifice some wet traction with wider tires, but in small increments it shouldn't matter much.

    It sounds like you should get a name brand all season tire, probably in stock width. Pick out one that is highly rated on the Tire Rack's website.

    BTW, wider tires probably didn't mess up your suspension, but they may have made your messed up suspension more obvious.


  6. #6
    Flashaholic* 9volt's Avatar
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    Default Re: Help me decide new tire width.

    Quote Originally Posted by LEDagent
    Can anyone tell me the negatives and positives (if any) for choosing 205/60/15 or 195/65/15? All the comments i've read at other forums are too focused on performance and style. I've outgrown all (most) of that but i've become very comfortable with the plus one size.
    205s on your car will give you slightly better traction in the dry (braking and cornering), slightly reduced gas mileage, slightly less traction in the wet, slightly more noise, and possibly some speedometer variance, but not much. I'd get the 205s personally.

    Also, "plus one" genereally means +1 inch in wheel size, not changing tire size on existing wheels.

    What tires are you looking at? That is a bigger deal than the size.
    Last edited by 9volt; 03-17-2007 at 10:10 AM.


  7. #7
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    Default Re: Help me decide new tire width.

    my stock tires were 205/65/16, and i changed to 215/60/16(goodyear tripletred) in front and 225/55/60(goodyear eagle f1) in back. i researched the sizes to make sure the diameters were withing mm's so as not to offset the speedometer. here are my impressions:


    fuel economy: slightly worse, maybe a mile or two less per gallon.

    braking: alot better. due to more surface area of the tire touching the ground.

    handling: better handling but a little more bumpier (can feel the road a alot more)

    performance: acceleration slightly slower but not by much, but more control especially on freeway.

    noise: definitely more noise.

    so overall, i like the change. better handling and braking and more control at higher speeds makes me feel a lot safer than before. i really don't mind the the slight difference in gas mileage. i don't mind the noise either but some might since it is a lot louder. btw, my stock tires were michelins.

  8. #8
    Flashaholic* cratz2's Avatar
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    Default Re: Help me decide new tire width.

    Honestly, I don't think that a mostly conservative driver would see ANY difference in wear and tear/suspension/brake issues when going from a 205 to a 215 with the same sidewall ratio and the same make and model of tire.

    I will say that there are TREMENDOUS differences between different tires though, even in the same stated category. My 99 Civic Si had Michelin MXV4s sized 195/55-15, I think. I replaced them with Bridgestone Potenza 750s sized 205-50-15 and every form of grip was radically improved. Dry and esp wet. After the change, the car gripped nearly as much in the wet as the stock tires did in the dry. The tires were a bit more quiet than the worn Michelins, but I can't say if they were any more quiet than the Michelins were when they were new. They also seemed to last longer. The stock tires were worn out in about 28,000 miles as I recall. I kept the car until it had about 65,000 miles and at that point, the 750s had more tread left, had more miles on them AND were driven harder. Now, the 750s are a summer or 3 season tire and they are NOT to be used on snow or ice at all. They came with a waver that I was supposed to sign, which I was never asked to sign.

    My 98 SVT Contour came with Goodyear GSCs. These tires were not well received with the SVT and they were quickly replaced as an OEM tire with the Goodrich G Force KD which is a pretty agressive tire. With the G Force tire, the SVT Contour had such a marked increase in grip, that it felt like a different car. Most magazines measured over .9G lateral with the KDs. But they didn't wear very well at all. Anyway, they were sized 205-55-16 and I replaced them with Continental ContiExtreme Contact sized 215-50-16 and again, the improvement was nothing short of overwhelming. The tires were also more quiet and more comfortable over rough streets. Handling near the limit was much more progressive and predictable. Something else to keep in mid is that the GSCs are not for use on ice or snow while the Continentals have exceptionally good snow/ice performance.

    My friend also happened to have a 98 SVT Contour with the G Force tires and eventually replaced them Bridgestone 820 or 830s or maybe 850s. 800 something series and they are no longer made it seems. The KDs are awesome tires but again, not for winter use while the Bridgestones were very comparable to my Continentals. Not quite as much grip as the KDs, but more predictable and much for comfortable on longer trips.

    Unless the tire is actually too wide for the car and rubs the inside of the fender well (which will be noisy) or a suspension component (which won't be very noisy), I doubt you'll see any difference with steering or suspension wear or performance. On my 88 BMW 535is, I went from an all season 205TRX tire to 235-40-18 which had literally twice the grip and the steering was not more difficult at all. This is pretty much the most extreme case between two tires you could possibly find so I'm sure with two different all season tires with only 1cm wider tread, there shouldn't be any difference.

    Fuel economy will ALWAYS drop when going from one tire to the identical tire with a wider tread, but 'should be' only about a 2% difference. Not even 1MPG if you keep exactly the same driving style which is difficult to do if you are the type of person that wants a larger tire for performance reasons. And of course, there will be a slight increased chance of hydroplaning with all the other factors the same except tire width but in my 16 years of fairly agressive driving, I've never hydroplaned once unless it was intentionally induced.
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