drslash (banned)Goya Asma join:2002-02-18 Marion, IA |
drslash (banned)
Member
2014-Dec-2 4:01 pm
Spare tire smaller than the 4 regular tiresI bought 4 like new rims with like new tires mounted. I posted this earlier: » GM truck rims And thanks to those who helped out. I did not buy a matching spare tire rim and tire to match new rims and tures. The old rims are 17" and the new rims are 18". My question is, will it be ok to run the 17" rim spare with the other 3 18" rims and tires should I have the need to put the spare on? My guess is that it will be ok to do this for a short time until I can get the flat to a shop and fixed. Thanks. |
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The overall diameter of the 17 inch tire needs to be the same as the overall diameter of the 18 inch tire. You needed to use the +0 concept of increasing wheel diameter while keeping the overall tire diameter the same. |
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davidhoffman |
to drslash
Using this website » www.sizemytires.com/calc ··· /compare I got that 265/60R18 is a plus 0 tire size for 245/70R17. |
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davidhoffman |
to drslash
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drslash (banned)Goya Asma join:2002-02-18 Marion, IA |
drslash (banned)
Member
2014-Dec-3 12:13 pm
Thanks for that information. |
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skipon11 Premium Member join:2005-06-09 Pittsburgh, PA |
to drslash
I think you mean driving with one of the old 17" rim and tires mixed with the new 18" rims and tires. I would not do that at highway speeds. It would affect handling. At very slow speed for very short distance maybe ok. I know here in PA. such a mix would not pass safety inspection,so it is considered unsafe. |
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The OP did state he was only going to use it as a spare until he got the bad tire repaired or replaced. Since he is concerned with the look of the vehicle, I am sure he will not be driving around with one old corroded wheel for more than absolutely necessary. As far as driving at highway velocities, there will be slightly less drag on the old 17 inch tire as it is narrower and you might get some not perfect steering. The set up is much better than the mini spare tires that are not even the same diameter as the originals. Those set ups are really bad. If he has the diameters extremely close it should handle OK at reasonable highway speeds. It would be smart for him to save up to get a properly same sized spare wheel tire combination in the future. |
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Anonymous_Anonymous Premium Member join:2004-06-21 127.0.0.1 |
to skipon11
said by skipon11:I think you mean driving with one of the old 17" rim and tires mixed with the new 18" rims and tires. I would not do that at highway speeds. It would affect handling. At very slow speed for very short distance maybe ok. I know here in PA. such a mix would not pass safety inspection,so it is considered unsafe. lot of cars have mixed tire size Most important is the rating of the tire rather then the size. You want the value to be equal or better for the Load rating but like a normal spare you have to keep it under 50mph I use mixed tire size on my car 215/65/16 on the front and 225/60/16 for the rears but the load rating is better on the 215/65. Rated for 100 index while the rears are rated for 98 load index |
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to drslash
You can mix wheels without any serious side effect as long as the tires are reasonably close to each other -- outside diameter, width, and tread. You just need to be more careful on slick surfaces. BTW, the diameter of the wheel doesn't really matter -- it's the outside diameter of the tire that you need to worry about most.
What size did you get on the 18" wheels, and what's on the 17" wheels? |
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to Anonymous_
In this case of using the old wheel tire combination as a spare, you would have two different tire sizes on the same axle. The overall tire diameter might be the same, but the tread width would not. |
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to drslash
The only thing that can cause trouble with a mixed-diameter setup is when the two different sizes are placed on a limited-slip axle, or either axle of a 4WD vehicle when the transfer case is in "locked" mode.
I am speaking about a temporary situation only, as there are many restrictions on different wheel/tire sizes when dealing with a 4WD or AWD vehicle. For obvious reasons, equal sizes must be maintained or drivetrain "wind-up" will occur.
In general, I would recommend having a spare the same size (overall diameter) as the existing wheels whenever you are dealing with 4WD or AWD.
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carlm13 to drslash
Anon
2014-Dec-4 11:24 am
to drslash
it would be OK to use the smaller tire as a "get you home emergency" and keep your speed down, dont go howling down the highway at 120kmh. And certainly dont drive around on it for days. a few manufactures fit smaller space tires in the trunk and call them "spacesavers" and they are intended ONLY to get you home or to a repair shop. running a tire/wheel that is smaller than the other ones on the car can cause issues with ABS, traction control, vehicle speed sensing and also put stress on your differential and [ if you have it] 4 wheel drive system so you want to use the smaller tire for as short a time as possible. |
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Anonymous_Anonymous Premium Member join:2004-06-21 127.0.0.1 |
to davidhoffman
Best way to solve this IS FOR him to buy a 18" steel rim and the same tire size as the other ones |
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Yes. |
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drslash (banned)Goya Asma join:2002-02-18 Marion, IA |
drslash (banned)
Member
2014-Dec-5 1:17 pm
Thanks for all of the information from everybody. The current spare has a 17" rim with an overall tire diameter about 1" less than the 18" rims and tires have on the vehicle. I plan on replacing the spare with a proper sized rim and tire in the future. Until then I would only use the current spare to get me to a shop in an emergency. The pickup involved is 2WD but has skid control so I don't know if the limited slip issue applies. See this before and after of the pickup. |
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skipon11 Premium Member join:2005-06-09 Pittsburgh, PA |
to Anonymous_
Yes,your not mixing sizes on the same axle,so your good to go. Mixing tire size on the same axle is when it gets bad. |
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to drslash
said by drslash:I don't know if the limited slip issue applie I think you're fine like that. If you have a limited slip differential and have a flat rear tire, you might consider putting the spare in the front and use the front tire in the rear. That would avoid any size difference that cause odd behavior when you hit the gas and avoid and potential damage to the limited slip. You might hit up a tire shop and see if they have any used tires in the right size to stick on the old rim. It's not like you need anything with a whole lot of tread left. |
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drslash (banned)Goya Asma join:2002-02-18 Marion, IA |
drslash (banned)
Member
2014-Dec-5 4:35 pm
Yes, I am going to get a different tire for the spare and a different rim. Current spare rim is 17". I need an 18" rim since the good tires are on 18" rims.
This whole experience also saved me a pain in the neck if I do indeed get a flat. When I had the truck in the shop I asked them to take the spare off and check it. The shop could not get the spare unmounted. The spare tire winch was corroded and froze up. They cut it off and installed a new spare tire winch. Let that be a lesson to others who have the spare tire mounted under the truck. The spare rim and mechanism get corroded. If I had a flat I would not have been able to dismount the spare. |
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shdesignsPowered By Infinite Improbabilty Drive Premium Member join:2000-12-01 Stone Mountain, GA |
I'd just get a cheap tire with the same diameter for one of your 17" rims to use as a spare. |
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