AMC Eagle Den Forum
The Shop => Suspension, Steering, Brakes, Wheels & Tires => Topic started by: IowaEagle on December 16, 2007, 06:52:52 PM
-
Jurjen found this handy tire calculator to help with your decision making.
http://www.1010tires.com/TireSizeCalculator.asp?action=submit&reset=yes
-
225 / 65/ 15 matches tire hgt dementions exactly!!!! for oem Eagle tires 195/75/15
-
Wasn't the factory upgrade a 205 or 215 65/15, not 225?
-
The main concerns for tire size (without considering mods to the wheel well) are width and outside diameter. I believe, and please correct me if I am wrong, that I read somewhere else on the nest that the max width for tires (without rubbing) is 225. You can play with the rim and sidewall dimensions as much as you want as long as the overall diameter stays within about 5% of original. Too small or big and you will get an incorrect reading from the speedometer. Although the speedo is hooked to the tranny, it is calibrated for a certain tire size. So the tranny will be doing 55mph, but the wheels may be moving faster or slower depending on diameter.
Cheers
-
Our speedos are hooked to the transfer case -- but yes, you are correct.
-
Kammback has 205 Firestones, wagon has 215 BFGs, no rub :)
-
My latest SX4 had 215/75s on it and they didn't rub, but the PO may have done some trim trimming that I haven't noticed yet. They're about 6% oversize.
-
Wasn't the factory upgrade a 205 or 215 65/15, not 225?
Yeah, the factory spec for the sport tires is 215/65 Goodyear Eagle GT. That's what I went for on my Kammback. They're not huge or anything, but definitely much beefier than stock. There is plenty of room for more tire, though.
mike
-
Hey Wizard, The ( 75 ) is why you might get some rub, I want to fill those old oversized wheel wells as much as possible without cutting or lifting anything so when the time comes I'll go with the 225/65/15's. I got a set of those Jeep hurricane style wheels on auction but they will need a lot of work.
-
Im runnin 235/75/15s i think theres a bit of lift but the springs r so sagged its prolly null... I custom aligned mine 2 set the tires dead center of the wheel wells... I get just a hint of rubbing when im at a steering angle where the outter wheel edges touch the inner lower edge of the wells in its sweep... If i raise it about an inch, or suck those corners back about 3/8 of an inch im sure theyd clear.. See my project thread 4 pics as proof.. Lol i should hav new springs n shocks on order 2morro.. With those they shld clear with ease well enough im speculating!
-
So, would the 225/65/15 fit on the stock Eagle rim?
-
I think they would, there's plenty of clearance under my car...
-
if i ever get around to afford new tires i'll try the 225/65/15 s n see how they do... nice thing is i work at a fountain tire so i can have swapped for a bit smaller if needed. With my 235/75/15s they just barely rub, and just a hair or two smalller should be good...
-
I'm curious about the offset... I went to a tire place to look at rims today and I told them "Jeep" wheels to keep it simple. I told them it was for an 80's style 5-lug Jeep.... then he asked a bunch of questions and I ended up telling him it was an Eagle and he looked up some info on his handy dandy computer and he said our Eagles have a front wheel drive offset...
is this true? or was he mistaken? I know my Blazer had a wierd offset and I hated it... but I never remember my SX4 giving me any issues. I could simply slap any Jeep wheel on and go.
My Eagle is a 1980 model... does that make a diference?
-
You sure the genius wasn't thinking Mitsu-Eagle? They are front drive.
-
Memory check please. I seem to recall Eagles as having 60 series tires when they came out instead of 65s. After 30 years & a memory that lies to me ( A LOT ). I was wanting to check. Think the original choices were 78s ( don't think they even make them now, replaced by 75s ) & 60s.
-
You sure the genius wasn't thinking Mitsu-Eagle? They are front drive.
Yeah, the first question was "Eagle Talon?".... *sigh* I get so tired of hearing that. He was "sure" that he knew he was right about the AMC Eagle though...
The front is wider set thanthe back for stability on eagles
So... just like most other 4x4's... but you don't have to do that right? You can use the exact same rim all the way around, correct? I remember the offset on my Blazer was retarded... I mean, if you looked at it at the right angle - you could clearly see that the front wheels stuck out further than the rear. I hated that.
-
Did he mean the front wheels have a different offset from the rear?
I have rotated front to rear and vice versa, and I'm sure most others have, too.
-
Yeah thatsd what he said... Ive always swaped wheels all over and never worried about it either.
-
Front or rear from the factory are the same.
-
Front or rear from the factory are the same.
Thats what I thought about the wheels as well. Thanks for all the extra info guys! So when the next tire guy argues with me... I can tell him to zip it and give me the same wheels all around. Thanks... I just wanted to confirm before I started waving my finger around like a know-it-all, LOL!
-
Jurjen found this handy tire calculator to help with your decision making.
http://www.1010tires.com/TireSizeCalculator.asp?action=submit&reset=yes
Thats a nice tire calculator....I'll have to bookmark that as it's very nice. I have long kept the Miata link that's also worked well over the years handy. They have a visual with theirs as well, along with much of the same comparison data, so both are well worth having handy. Here's the link to that if anyone is interested:
http://www.miata.net/garage/tirecalc.html
-
Just tried to put Eagle 15 inchers on my Gremlin, the front wheels won't clear the Gremlin disk brakes. I'm using Fords on the front and Chyslers on the rear to fit 15s on my Gremlin now.
-
Are the Eagles rims 6 inches wide? If so I could use these on my studebaker too!!
-
If my memory isn't lying again, they are.
-
Yes, the stock steel wheels are 6"
-
So... the 235/70R15's are just a hair over 5% larger... do you think they would work? or do you think my best bet for max width would be to just stick with the 235/65R15's?
I had the 235/75R15's and they are WAY too big... can't turn at all... and that's without the trim. Granted... the springs are 25yrs old and the shocks aren't the best... but still.
I'm wondering if the 235/75R15's would fit with the 3" lift I got and havent installed yet. That doesn't include the new springs I bought for the car as well.
I just want the widest tire I can find without rubbing.
-
Im deff leaning toward the 235/70/15's... you think the 245/70/15's would be ok?
I can handle slight rubbing on heavy cornering... but once I get that lift I wouldn't think either would rub, Even still, I can handle a small amount of rubbing to give the car a beefier look.
I hate how the wheels are so skinny on Eagles... and they sit in so far from the body... especially with the wheel flares.. it just looks funny especially on the wagons.
Im leaning toward spacers on the back at this point to make the stick out a bit futher. How big is the biggest spacer? lol An inch would be perfect along with the 235/7015's....
opinions?
-
I've checked through most of the posts, and really couldn't find the exact answer I'm looking for, so I decided to just post the question: I'm looking to buy a 1984 Eagle and would like to put on some Goodyear Wrangler Silent Armor tires. The problem is, the smallest size they come in is 30x9.5R15. How much modification would it take to run this size tire? I plan on buying new shocks and springs right away and hope this will give it enough natural lift to fit them, just not sure if it will be enough. Any and all answers will be helpful and much appredicated!!!
-
HI Welcome to the nest and thank you for bringing up this post this is grate ......AS for as mods to suspension I think you can raise an eagle 2" after that you have to start changing parts...Maverick or one of the
outhers can help you with that............Don
-
Years ago I made my own tire size calculator in excel. Not difficult and works great. I also have one that tells me what speedo driven gear I need for any particular tire size and differential gears.
-
I have that size on my car now(fenders trimmed) you'll want to change the gears in both axles to something steeper like 3.54:1,I didn't and toasted my trans(rebuilding that) the back has 3" blocks and longer u bolts a helper spring,aftermarket shackles and 2 stud lengtheners on each shock for about 5" lift,the front has those mr.Gasket spacers which were too extended,causing one to snap.A safer method is a spacer that sits in place of the top cushion,mine were 3 1/2 inch in the front (which causes cv axle noise) 2 inch max for no problems I've read here.Hope this helps
-
Be warned that if you go from a 75 Series tire to a 65 Series tire YOU WILL LOSE GROUND CLEARANCE !!!
I did that to my Eagle and regretted it later on. I noticed my Eagle would scrape on obstructions that it used to be able to clear. Thank goodness for the skidplate!
Was very happy when the tires finally wore out and I was able to go back to the 75's ;D
~ Joe in NY
-
Go to an 85 series and you'll GAIN groundclearance plus the tire will be narrower for better clearance from the fender.
-
Go to an 85 series and you'll GAIN groundclearance plus the tire will be narrower for better clearance from the fender.
Now THAT sounds even better! ;D
Probably have to step up to a 16" rim to do that.
I wonder if an LT215/85R16 would fit in the wheelwell without any clearance problems. ???
~ Joe in NY
-
Awww.
Just tried the Tire Size Calculator here and a warning came up that said you shouldn't increase the tire diameter any more than 3% over the stock tire or you risk brake failure.
The Diameter Difference with the LT215/85R16 tire is 12.74%
Oh well... :(
~ Joe in NY
-
Awww.
Just tried the Tire Size Calculator here and a warning came up that said you shouldn't increase the tire diameter any more than 3% over the stock tire or you risk brake failure.
The Diameter Difference with the LT215/85R16 tire is 12.74%
Oh well... :(
~ Joe in NY
More total diameter is what will get you "more clearance". A 215/85/16 is over 30" in diameter and will need a lot of fender work or a big lift to get it to work.
-
my oversized tires smoked my tranny,I had 30x9.5 x15's just fyi.and the front fenders were cut by the p.o.
-
Yeah.... I'll just stick with my 75's.
I don't need any MORE problems with my Eagle than I already have! :o
~ Joe in NY
-
Awww.
Just tried the Tire Size Calculator here and a warning came up that said you shouldn't increase the tire diameter any more than 3% over the stock tire or you risk brake failure.
The Diameter Difference with the LT215/85R16 tire is 12.74%
Oh well... :(
~ Joe in NY
The reason they state that is for liability reasons.
Anything more than 3% will throw your speedometer off [You'd be amazed how many people have installed huge tires on their car/truck, only to come back with a ticket saying its our fault.]
Secondly, is that a lot of people with 4x4's, try to cheap out and change only two tires. When you have something like huge mud terrains or swampers, the difference in worn out tread can actually equal 3% or more, causing all sorts of drivetrain issues. All of our suppliers require four tires, of the exact same brand and model to be installed on any 4x4. Most people don't realize, two tires of different brand, but same size aren't actually identical in diameter. You can get a 33x10.5R15 say, That can range anywhere from 31.5-33.5" tall [In extreme cases]. Same thing with performance tires. Nitto 555R's are a great tire, I've personally used them.. but their 275's were narrower than my BFG 265's.
The 3% rule is also because a lot of people put big tires and rims on their vehicles, without ever upgrading their braking system. We get people all the time with jacked up SUV's who wonder why it takes a lot longer to stop, going from a stock 28-29" tire, to a 35" tire. It doesn't seem like THAT much heavier [it is lifting it, I assure you ;D], but it's all rotating mass. The vehicle weight only goes up by a bit, but it directly effects braking exponentially, which creates significantly more heat, hence the possibility of brake failure. I'd say 1/10 [if that] people I see who put on significantly bigger rims or tires upgrade their braking system. We also have a few vehicles per month come in, where the older style ABS sensors trigger due to increased diameter. The newer style TPMS sensors don't matter on diameter at all.
Some manufacturers will also void a warranty on the vehicle if you go out of 3%, regardless if you change all four or not. I know we had an issue with an Acura MDX, customer came in, wanted bigger tires, Acura has a note in our system to contact the dealer because they do not want anything larger or smaller installed. Called the dealer, they basically said any mechanical failures are the responsibility of the client, Acura does not condone tire size changes with their AWD vehicles.
Also anything over 3% will change the ride and handling of the vehicle. Too tall of a sidewall and the vehicle will feel 'squishy' compared to stock, and it will generally made handling a lot less responsive. Too short of a sidewall, and I hope you know a good back surgeon. The vehicle will respond quicker but at a massive sacrifice to ride comfort.
One of the problems we also see a lot, is putting putting super wide tires on their cars/trucks, and then not being able to drive through rain or snow. In wet weather, a narrower tire will do better as it has more pounds per square inch of force pushing down and makes it harder to hydroplane. In dry weather a wider tire generally causes more traction under heavy acceleration. In 'thick' mud, a wider tire is generally better. On ice, with a good ice tire you also want a wider tire as it has more surface area and a bigger contact patch. Most often, it's not worth the loss in snow traction to get a little bit better ice traction, and this doesn't apply to 'general snow tires' Only specialty ice tires. So it's best to find a good all around balance in size.
All of that being said. Too heavy of a tire can/will cook your brakes during a hard stop from highway speeds. Stock braking systems are rarely designed to handle an excessive increase in tire weight, which can cause your brakes to absorb more heat than they are designed for, causing brake failure. It can also cause an excessive strain on your transmission and engine if your vehicle does not have the power to handle it. Putting significantly bigger tires on something with a weak transmission is never advised.
Basically, it's not 'unsafe' as long as you realize your braking and handling could be adversely effected and you stay within reason. It's there so the guy running 37" Super Swamper's on stock tiny brakes can't come back and complain when his brakes are a smoking pile from repeated hard stops from highway speeds, or wonder why his transmission has no first gear anything, trying to push 37's up a hill from a stop every day.
Sorry for the incredibly long winded response haha.. I've dealt with this question a billion times, and I've spoke to some of our suppliers about it in detail.. So I figured I'd share what they have to say.
-
It isn't a weight factor doing in the brakes. It's the lever principle. Bigger tire diameter = smaller brake effectiveness to stop the big tires.
-
It isn't a weight factor doing in the brakes. It's the lever principle. Bigger tire diameter = smaller brake effectiveness to stop the big tires.
I was sent to a seminar for Bridgestone and they touched on this subject, because their Potenza line was getting a ton of people complaining about increased braking distance. They had the results from a test using 3 identical cars, same size tires, and three different styles of rims. Light weight race rims, standard rims, and heavier aftermarket rims of the same size. There was a pretty noticeable difference in heat and braking distance in each increment. Combine that with the fact that Potenza's are one of the heavier tires in their class is probably why they were getting so many complaints. Their point was people were upgrading to aftermarket rims and Potenza's, and complaining it didn't stop as well, even with the same diameter tires. Their focus wasn't rotor heat, but it was included in the test. In every increment the weight went up of the tire/rim package, the measured temperature of the rotor went up. I'll see if I still have the 'book' they gave us. It was included in there, if I can find it.. I'll scan it and post it up.
I always just assumed that it was a diameter issue as well, it's simple physics larger diameter takes more to stop from a smaller brake, but according to their study It also very much has to do with weight. Which, also makes sense if you think about it.
You are right, but I was trying to cover all the bases, and I remembered that seminar I had to attend and that was their explanation for it. I also wrote it after I had just woken up [still in bed haha] from being out until 5AM ;D,
I also think the complaints were just because Potenza's are horrible tires.. hah.
-
LOL! The tire size increase however does the same thing to the brakes as it does to the axles. Taller tires = higher gear ratio (the bad way. It takes away engine power and bottom end) It does the same things to brakes. Longer to take off, and longer to stop.
-
LOL! The tire size increase however does the same thing to the brakes as it does to the axles. Taller tires = higher gear ratio (the bad way. It takes away engine power and bottom end) It does the same things to brakes. Longer to take off, and longer to stop.
Yep. Totally true. That's another complaint we often get. "Well the car has less power now" with significantly bigger tires. Even though it was explained about differential ratios vs tire diameter prior to the install.
You can never please people. ??? I'm sure you've had your fair share too hah.
Tire size affects a lot more than people realize.
There is so many variables to consider.
-
I got 215/70/R15 an no rub so far looking to go with better set of tires this year.
-
My 235/75/15s will be much nicer with 3.08 gears (vs the 2.72 currently in there) since I also put in a 727 (which takes a bit more power to get rolling due to inertia and first/second gear ratios being taller than 998s.
-
I just picked up a 1981 SX/4 with brand new Open Country 225/75 R15's. They rub a bit when I turn hard. I really do not want to trim the fender flares at all. The current 225/75 R15's per the tire calculator I found are 28.3" diameter. My thought are the following sizes. I want the largest size I can get without rub. I fear of buying new tires just to be in the same boat I am now with the 225/75 R15's. Thoughts? I'm probably rolling with the 215/70's as I've seen a post that there is no rub.
215/70 R15 @ 26.9" diameter
or
215/75 R15 @ 27.7" diameter
-
I have 215/70R16s on my Kammback. At the time I bought them we also test fitted the next larger size (which I believe was 215/75 but could have been 225/70) and there was going to be some rubbing so that's why I went with the 215/70. A lot depends on what kind of shape your suspension is in and backspacing on your wheels. Good luck, let us know what you choose!
-
My wagon has Goodyear 215 - 75 - 15 Wranglers & I get a little bit of rub sometimes. Just found out about a week or two ago that they're cracked/dry rotted so I'm going to a Goodyear Ultra Grip in 205 - 70 - 15 & see how they fit. On the sedan I have 2 Kelly Springfield Explorer 215 - 70 - 15 on right now & am putting 2 Goodyear Integrity 215 - 70 - 15s on for the other 2. I had the Kellys left over from BlackBird. It had 4 nearly new tires & I sold the 2 Goodyears to a friend after it got totaled out. I couldn't find two more to put on, so I WAS gonna use Goodyear Vivas from wally's world, but they went on back order after I ordered them. So I went with the Goodyear Integritys. I'll see how they fit when they get here. DUE to the shop Tues., MAYBE I can finally get it on the road then. I've had it ALMOST a month now & have yet to drive it! Brought it back from Wisc. on a dolly (hence the 2 Kellys, the old tires were actually PEELING apart like a recap, it had been sitting that long) & dropped it at the shop the next day. As far as I know, that's all that's left.
-
I am running General Grabber atx 225 70 15 which is 27.4 inches I trimmed the aft inner corner just a little for extra clearance https://www.tirerack.com/tires/Spec.jsp?tireMake=General&tireModel=Grabber+A%2FTX (https://live.staticflickr.com/65535/51196770093_41045ee31b_k.jpg) (https://flic.kr/p/2m15Q5D)A488231B-CF43-48D7-8A7F-DC6DD784822D (https://flic.kr/p/2m15Q5D) by rmick1 (https://www.flickr.com/photos/amcnut/), on Flickr
-
Hi guys, we are bringing a 1981 eagle, stock/original suspension/ride height down from Idaho in a couple weeks, and previous owner states the tyres are old and cracking sidewalls.
So we have to replace them, and we live in snow country where our tyres need to be snow rated.
What is the biggest size tyre that can be mounted with no, or minimal shaving inside of plastic fender flares, so you do not hear any rubbing when turning sharply?
Any brand/model that is better performing in snow/ice?
From what I have been able to gather, 215-70-15 or 205-75-15 tyres might be the limit? Anyone have any experience? I want to increase the clearance of differential to ground as much as possible.
Thanks!
-
I run General Grabber 225-70-15 with a 2 inch lift Had to do minimal trim on inner corner of flare. You can see diameters under specs. https://www.tirerack.com/tires/general-grabber-a-tx
-
I think that the sizes you mention are about the best you will do without a lift like rmick did. Good luck!