#9316, "RE: Tire/Wheel Size question..." In response to Reply # 1
right now ive got a set of 16's ive had for a few years on my 1G, i sold that and put the rims on my new 2G, theyve got 205-55-16's on them if that gives you a basis on where i need to go
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I used to have a 420A...
'92 TSi AWD
11.8 @ 119mph 470awhp 405 ft/lb torque 30psi on E85 w/ Borg Warner S256 Turbo
#9317, "RE: Tire/Wheel Size question..." In response to Reply # 2
heh well here's a good way to check how much your off. if you ever see those speed meter thingies they put on the side of the road that say how fast your going check it out and check how much your speedo reads. i'm off by like 5 mph no matter what haha.
http://www.hadesomega.info -car specz and movies 95 Eclipse RS | 76' 280Z | 89' MR2 | 99 Neon | 91 Zephyr Who sez FF can't drift?
#9318, "RE: Tire/Wheel Size question..." In response to Reply # 0
Yeah i was told that those speed meter signs aren't very accurate. But with my 225-45-17's, my speedo read 30 mhp, and the sign read 27 mph, so according to that speed sign, i was going around 3 mph slower than what my car was reading. I want to pace a friends car on the road to see what that says, to make sure.
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#9319, "RE: Tire/Wheel Size question..." In response to Reply # 4
The speedometer is supposedly-allegedly calibrated to the stock setup. If you change the overall height of the tire then you're speedometer will off by the percentage difference in tire circumference. I had an 81' AMC spirit with 275/60s on the rear(definately not stock) - the circumference difference was 15%, so my speedometer was always 15% off. When I was showing 60 on the speedometer, I was actually going 69...70 was 80.1, 80 was 92, and redline in 4th gear showed 120 which was 138MPH!! }> I should have swapped it out for a 5 speed...the motor was probably good for 160mph
Anyway, thats the deal. So if you are concerned with impact on speedometer, the trick is trying to match the new wheels to the original ones. I need some new feet as well and I put together a spreadsheet to analyze tire/wheel matchup. You can download it here http://www.users.fast.net/~metaljim/WheelWorkshop.xls
Basically all you have to do is enter the section width, aspect ratio, and rim diameter. The numbers in blue are automatically calculated. Off to the right(for your benefit) i put in the calculation for underdrive percentage from stock. You can see that the po-mobile(lo-pro on stock rims) would be 14% off.
Just so you know - it is fairly easy to get used to the percentage calculation on the fly. Eventually it becomes automatic.
Hope this helps.
95 Eclipse RS : 5 speed Gude cams : test pipe : CAI : Dual air horns : Kenwood KDC 5000 incomming - lower strut bars : AutoCommand remote start
#9320, "RE: Tire/Wheel Size question..." In response to Reply # 5
your spreadsheet is off. pretty bad too. anyhow. for 17's your going to want 215 45's or ss5 45's. 205 40's will work your speedo will be off a little bit but you'll also save more money compared to the other sizes.
#9321, "RE: Tire/Wheel Size question..." In response to Reply # 6
No way buggy boy. The spreadsheet works like a charm. Did you even download it and try it out?
If your problem is what tires I gave as examples on the spreadsheet...they don't have anything to do with the spreadsheet. They're just examples. Maybe it would help you guys out in Lancaster if I explained the examples in more detail:
Stock RS - This is the stock tire for my 95 RS
po-mobile - This is a cheap alternative for getting low profile tires. If you can't afford bigger rims but you just can't stand the way the tires buckle under drift, you COULD shorten the aspect ratio a bit. With this example, I also pushed the section width out 10mm for that really fat look. But you don't want to go too much wider then the stock 7.68 inch contact width, especially with almost a 2 inch drop in side height, because you still have to keep them on the 14x5.5s. Isn't it obvious that this is a joke example? It's the po-mobile for christ's sake!
nice - This is what I'd get. This would be slamming on some Borbet Type E 17x8s...but thats just me.
lottery - This is what I'd get if I won the lottery....along with one of everything from HRC.
I don't know if you were paying attention, but the original question was -
>If i go with 17" wheels what tire size do i need to go with so the speedometer will register the same, what about with 18"s??
The spreadsheet is a tool to figure this out. The image I put up with some examples are just that - examples. I didn't say go out and buy 19 inch rims and put some 245/30s on em(unless of course you just won the lottery). I haven't said a damn thing about what size to put on. All I'm saying is that I put together a spreadsheet as a tool to HELP FIGURE OUT what to do about tire/rim sizing. Along with a little guidance about calculating speedometer mismatch percentages that included a reference to my experience with calculating them. I'm just trying to be helpful here.
Could you do the same and help me with this - Whats your problem with the spreadsheet?
95 Eclipse RS : 5 speed Gude cams : test pipe : CAI : Dual air horns : Kenwood KDC 5000 incomming - lower strut bars : AutoCommand remote start
#9322, "RE: Tire/Wheel Size question..." In response to Reply # 7
Any time you change the overall diameter of your wheels from the stock setting your speedo will be off no matter what. The only way to fix it is to go somewhere like a dealer or something and have it recalibrated. If you want to know how far you are off, try asking a highway patrolman,nicely, to pace you up to the legal limit on a highway and MAKE SURE you tell him/her that you want to find out how far off your speedo is. Usually they comply.
MachV.com has a tire size guide and a brief explanation of all the numbers, eg aspect ratio, etc. According to them if you came stock with the 14" wheels and you want 17"x7" wheels then you need about a 205/40 sized tire to keep the stock diameter, but you could go as wide as 215/40. Hope this helps.
Dave "The Bald Bull" 97 RS Member of the infamous Barcelona Red Crew
"Free people will never remain free, if they are not willing, if need be, to fight for their vital interests"
"It is better to have died in the ranks of the vanquished warriors th
#9323, "RE: Tire/Wheel Size question..." In response to Reply # 8
yeah and while your at it call sears and tell them that thy're managers don't know how to train there associates cause that's what the fuck i am. i know my tires ass. first of all a 235 40 17 will not fit on our cars without rubbing that's why the guys on 19's have to roll 225 35's. you'll never fit more than an 8 inch wide rim under our car. therefore your spreadsheet is for shit cause it is explaining how to upsize tires and not how to upsize tires on the rim in question
#9324, "RE: Tire/Wheel Size question..." In response to Reply # 9
>yeah and while your at it call sears and tell them that >thy're managers don't know how to train there associates >cause that's what the fuck i am. i know my tires ass.
good for you
>first of all a 235 40 17 will not fit on our cars without >rubbing that's why the guys on 19's have to roll 225 35's.
>you'll never fit more than an 8 inch wide rim under our car.
bullshit. Someone on this board fit 3000GT VR-4 17x8.5 rims with with 245/45's on his. IMO - That is one fat ride.
> therefore your spreadsheet is for shit cause it is >explaining how to upsize tires
wrong - but at least we're finally back to the topic. Did you read Luke's question? The intent of publishing the spreadsheed was to help Luke, and the rest here on 2gnt, how to figure out the speedometer differences for different tire sizes using a simple little spreadsheet. Lets run Matt's wheel(the ever popular 225/45-17's) through the WheelWorkshop spreadsheet. It shows the speedometer should be off by .91%, so almost 1 percent. So if Matt is showing 100MPH on the speedometer, he is actually going 101. Basically that size is a pretty close match to stock...as far as the speedometer is concerned.
>and not how to upsize tires on the rim in question
No rim width has been specified, so there is not really a rim in question yet. At this point Luke's rims are hypothetically either 17 or 18 inch in diameter, no width specified...
...but since you brought it up. It's very simple to match a tire to a rim. All tires have a rim width range that basically dictates what size rim is safe for the tire. Also, each tire has a measured rim width or "design width", that basically is what the tire was designed to fit on. Different brands have different rim width ranges and measured rim widths. As long as your rim's width is within the tire's rim width range you should be fine.
Hope this helps
95 Eclipse RS : 5 speed Gude cams : test pipe : CAI : Dual air horns : Kenwood KDC 5000 incomming - lower strut bars : AutoCommand remote start
section width plus 10 aspect ration minus 5 rim diameter plus 1. that's how it works. 245 45 17's are mustang wheels i've worked on them my self they're 17x10 i can guarantee they either rub or stick out on an eclipse. 245 45 16's i've seen pics of the guy ont his board with them. his sidewalls are rolling over. i'm waiting for him to come up bitchin about either a blown tire from underinflation/heat or the beads straight poppin off the rim. i know what fits safely, it's my job.
"but since you brought it up. It's very simple to match a tire to a rim. All tires have a rim width range that basically dictates what size rim is safe for the tire. Also, each tire has a measured rim width or "design width", that basically is what the tire was designed to fit on. Different brands have different rim width ranges and measured rim widths. As long as your rim's width is within the tire's rim width range you should be fine"
no there's very strict standards as to measuring tire sizes. everything is regulated by the government. there is no slight difference between this rim and that. only difference is that there is a 15.5 inch rim and a 16.5 inch rim. both are for trucks and the difference is the bead is different because the lip on the wheel is angled at a different angleinflating a tire for a 16 inch rim on a 16.5 inch rim will make the tire explode in your face and kill you.
#9326, "RE: Tire/Wheel Size question..." In response to Reply # 9
I know a guy that has Enkei V1's 18x8.5 with 235/40-18 tires on his Eclipse right now. He had to roll the rear fenders but has no problem with rubbing. Plus it's lowered with ground control coilovers. So whoever thinks it can't be done....it can!
Anyway, here is a easy formula for calculating overall tire diameter: Here is an example of a 235/45-17 (sectoin width(235) x 0.aspect ratio(0.45))x 2 divided by 25.4(this number will never change) + wheel diameter(17) = Overall Diameter.
235 x .45= 105.75 105.75 x 2= 211.5 211.5/25.4= 8.32 8.32 + 17= 25.32
#9329, "RE: Tire/Wheel Size question..." In response to Reply # 13
Had to roll the fenders because of the drop, not just putting the wheels and tires on!! Take a poll and see how many people have rolled rear fenders on this board.....
05 STi