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Post by imaginarius on Apr 9, 2009 2:54:18 GMT -5
So, I would like to invest in lower profile wheels and tires, but don't worry, I see only 14's in my future! The current tires are fronts 155/80R13, rears 175/70R13. I read a bunch of threads concerning width, while I understand that, I am concerned about height. So...what ARE low profile tire measurements, and what should I look for?
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Post by ultima on Apr 9, 2009 5:44:26 GMT -5
I really hope you don't use different sized wheels at front/rear and at the same time uses 4wd. If you are looking for low profile I would search for tires with a profile around 45-50..
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Post by imaginarius on Apr 9, 2009 22:42:42 GMT -5
Oh, no, it's the '91 GL, so it's FWD...yeah, my brother-in-law gave it to me like that, so...but anyways, I'm going to assume the "70" and "80" numbers mean "profile"? So like, I'm pretty dumb, so you guys are gonna have to break it down for me. So I understand the R13 part, but what would the say..155 and 80 mean?
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SeattleJusty
No, a boxer will not fit in a Justy.
Posts: 1,587
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Post by SeattleJusty on Apr 10, 2009 1:40:13 GMT -5
OK here is how wacky half metric, half imperial tire measurements work. The tire will have a string of numbers & letters that will look like any of the following: - 205/55VR16
- 225/50ZR16
- 245/40ZR17
So the first number is your section width expressed in millimeters. This is not the effective width of the tire with respect to clearing your fenders or suspension but rather it is the width of the tread portion of the tire. The actual total width is a little bit wider still. The second number is the aspect ratio but you will never hear anyone call it that. The term most often used is "##-series" for example 50-series tire or 60-series tire. This is the profile of the sidewall expressed as a percentage of the section width. The last bit is the speed rating coupled with the imperial measurement of the wheel for which the tire fits. The first letter equals a speed rating for example V means safe up to 149MPH and Z means the tire is safe beyond 149 MPH. So a popular Justy tire is the 155/80R12 which literally means 155mm wide, with a sidewall 80% of the width (155X0.8=124mm) mounted to a 12" wheel + you can't go fast anyway so why bother with a speed rating ;D OK so you have two parts sidewall, one above the wheel and one below the wheel so 124X2=248+the size of the 12" wheel which is 305mm so 248=305=553mm total height and that comes out to 21.8" and guess what, according to Kumho, their 155/80R12 is exactly 21.8" tall. Hey guess what, stock Justy tire was 145R12. Well what does that mean? It's missing a bunch of info! When the aspect ratio is not expressed, it is to be assumed at 82%. 145R12=543mm~21.4" tall So what does all of this really mean? Well it means a bunch of stuff but the most important thing is to take a huge step back, rub your eyes and simplify it. Your Justy cannot swallow anything taller than a 22.7" tire. It doesn't matter if it is a 50-series, 60-series or 80-series. Your Justy can have a tires as wide as you want (within reason guys) but it will have to be mounted to a wheel with enough negative offset to clear the suspension. Then your only enemy is rubbing the fender lips and wearing out your ball-joints twice as fast as normal. A popular tire is a 175/70R13 as it fills up the wells with its 22.7" height and fills out the rims being more than an inch wider than a stock tire. You can also do a 185/60R13 which is 21.8" tall but you will have to use wheel spacers or wheels with a smaller positive offset<--- BTW there are very few choices in this size. You could go with a 185/60R14 at 22.7" tall, or a 195/45R15 at 21.9" tall, 195/50R15 also at 22.7" tall, 195/40R16 at 21.1" tall etc etc. just as long as you get the width & offset correct. Be warned though that once you get into the 14" and bigger range, not only do the wheels weigh more but the tires skyrocket in weight. You can make a Justy look pimp with some 15s but you'll be driving like a pimp too.... slllooooooow BTW 175/50R13 is 20" tall, damn near a half inch shorter than the 145R12s. I'm guessing that would put your RPM somewhere around 4300 to 4500 RPM just to go 70MPH on the freeway depending on which model Justy you have. Yikes! I hope some of this helps. Good luck tire shopping P.S. remember those tire examples I sited above? They are all the same height!!! - 205/55VR16
- 225/50ZR16
- 245/40ZR17
Yeah I know, blows yer mind. .
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Post by imaginarius on Apr 10, 2009 3:05:47 GMT -5
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SeattleJusty
No, a boxer will not fit in a Justy.
Posts: 1,587
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Post by SeattleJusty on Apr 10, 2009 9:58:46 GMT -5
Those wheels look like a great deal, thay just have to have a center bore of 59mm or bigger. BTW, some tires are better than others but there really isn't a such thing as a "bad tire". If you think about what a tire does and the abuse through which we put them, it is amazing that they last more than a year. Just the centrifigal forces alone, how does the steel stay in there without exploding!? Remember though, you do get what you pay for.
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Post by imaginarius on Apr 10, 2009 12:21:56 GMT -5
So that wheel and tire combo comes out to 548 dollars, 148 more than I paid for the car...so I hope I am getting a damned good deal. And as far as abuse...no, not for me. I have a family(as I have covered well) so I am into BETTER handling and style, so...
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Post by DrewNukesEm on Apr 27, 2009 23:03:33 GMT -5
BTW 175/50R13 is 20" tall, damn near a half inch shorter than the 145R12s. I'm guessing that would put your RPM somewhere around 4300 to 4500 RPM just to go 70MPH on the freeway depending on which model Justy you have. Yikes! . Is this because the overall wheel diameter is smaller therefore the wheel spins faster? So this means whatever tire/wheel package you decide, make sure it is around 21" tall total to not throw off the gears?
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Post by wrxisthebest on Apr 28, 2009 0:15:41 GMT -5
BTW 175/50R13 is 20" tall, damn near a half inch shorter than the 145R12s. I'm guessing that would put your RPM somewhere around 4300 to 4500 RPM just to go 70MPH on the freeway depending on which model Justy you have. Yikes! . Is this because the overall wheel diameter is smaller therefore the wheel spins faster? So this means whatever tire/wheel package you decide, make sure it is around 21" tall total to not throw off the gears? Yes, The larger the wheel is in total height the lower the RPM's compared to a certain speed. But also remember that using taller or shorter tires can also fluctuate your actual speedometer as well. the larger the tires the slower the car thinks it is going. This is due to the actual Speedometer sensors reading less revolutions that the tire is making.
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Post by imaginarius on Apr 28, 2009 3:11:33 GMT -5
Ok so, the tires currently remain the same, the fronts are still 155/80R13, the rears are still 175/70R13; most times in 3rd or above, maintaining speed is somewhere in the 3000 to 3100 range. However, when my wife yells at me to slow down in a 40 and I look at my speedo and it only says 35, well...we know where that can go. But when I also notice most traffic slowly drifting off behind me, the I know something is up. Now can that be a speedo adjustment, or is there such a thing? Or could it ultimately just be the tires....
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Post by DrewNukesEm on Apr 28, 2009 14:26:28 GMT -5
i'm not sure of any speedo adjustments.. i think the speedo runs off a cable that plugs from the back of your cluster to the tranny.. the cable is in a sleeve and spins as your tranny does.. which tells the speedo what to read.. i used to have a '63 vw beetle, in that the cable went from the back of the cluster and plugged into a spot for it in the middle of the front drivers side wheel and spun as fast as the wheel.. i had smaller wheels up front with low profile tires, and it threw my speedo off.. it made it read fast. anyways, i think newer cars are either electric or has a cable that plugs into the tranny like i said.. so i would point towards the different tire sizes being the cause..
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Post by wrxisthebest on Apr 28, 2009 17:12:14 GMT -5
i'm not sure of any speedo adjustments.. i think the speedo runs off a cable that plugs from the back of your cluster to the tranny.. the cable is in a sleeve and spins as your tranny does.. which tells the speedo what to read.. i used to have a '63 vw beetle, in that the cable went from the back of the cluster and plugged into a spot for it in the middle of the front drivers side wheel and spun as fast as the wheel.. i had smaller wheels up front with low profile tires, and it threw my speedo off.. it made it read fast. anyways, i think newer cars are either electric or has a cable that plugs into the tranny like i said.. so i would point towards the different tire sizes being the cause.. alot of newer cars run off the same way yours did... using magnets though
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Post by streetruler on May 1, 2009 13:35:24 GMT -5
if you put wider tires in front and narrower in the rear it cuts down on your turning radius a bit.
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Post by imaginarius on May 1, 2009 13:56:24 GMT -5
Why would that matter much? And I think I am gonna stick to 175/70R13's. They seem to have a decent, nifty low-profile look, and the Goodyear Viva's that are on them already have a sporty look, so I am gonna by 4 new ones from either Schwabbie's or Sears. And later get new wheels, but it's not a priority.
By the way, I saw a Ford Festiva yesterday downtown, but it looked like it was a bad-ass late 70's version. Very scary looking....
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SeattleJusty
No, a boxer will not fit in a Justy.
Posts: 1,587
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Post by SeattleJusty on May 1, 2009 18:56:27 GMT -5
if you put wider tires in front and narrower in the rear it cuts down on your turning radius a bit. Yes, this is a great idea, because if any car is dying for help on turning radius it must be the poor Justy. Wide tires in front, narrow tires in rear... 9" gain in turning radius well worth 2MPG that you lose.
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SeattleJusty
No, a boxer will not fit in a Justy.
Posts: 1,587
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Post by SeattleJusty on May 1, 2009 19:25:56 GMT -5
Why would that matter much? And I think I am gonna stick to 175/70R13's. They seem to have a decent, nifty low-profile look, and the Goodyear Viva's that are on them already have a sporty look, so I am gonna by 4 new ones from either Schwabbie's or Sears. And later get new wheels, but it's not a priority. By the way, I saw a Ford Festiva yesterday downtown, but it looked like it was a bad-ass late 70's version. Very scary looking.... Funny, I've always thought of 175/70s as a high profile. BTW that late 70s Ford would have been a Fiesta.
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Post by ultima on May 2, 2009 4:34:15 GMT -5
175/70 can't be low profiles, there's way to much rubber. I think that everything above ~50 can't be low profile.
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Post by imaginarius on May 3, 2009 21:30:37 GMT -5
Well now I am actually getting somewhere. **sarcsm button goes here o **So anything above 50 is NOT low profile....hmmm....I'll snap a pic later tonight and THEN give me your opinion. Honestly, I mean how much f-ing meat is too much for a damn Justy?
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SeattleJusty
No, a boxer will not fit in a Justy.
Posts: 1,587
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Post by SeattleJusty on May 3, 2009 23:58:34 GMT -5
S'not about that. The only thing that matters is keeping the tire under 23" tall.
50 series just means a percent. 50 series can be "low profile" or "high profile" just depends on the section width.
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Post by imaginarius on May 4, 2009 1:53:54 GMT -5
Well that was easy to clear up hehe, see the fronts are like freakin' donuts but the rears are...nice, smoother, looks....thinner heehee
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