Tire advice for 97 TJ

F

Finally

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Dec 17, 2020
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Location
London Ontario Canada
Hey folks. Looking for a little advice. Bought a used '97 TJ and don't like the tires. They
are after market 305/70R16 and very large for truck. Looking to downsize and get something
better quality. Have read and heard MANY recommendations and a variety of opinions. I think
i want something rugged looking but more suited for highway driving as i will rarely be taking it
off road.
I am leaning toward Toyo Open Country A/T 255/70R16. An original '97 came with 205-215"s so
an up size to 255 is a leap but much smaller than the 305's currently on now.

Any advise on whether i am going to small OR too large would be great. Looking forward to reading
some advice from Jeep owners and NOT tire salesman. Thanks
 
Few if any tire salesmen here.

305/70R16s are pretty damn large. Does your TJ have a lift? What is the backspacing on your wheels?
do your tires rub on anything when turning all the way?

I'm running 235/85R16s on mine with no lift and very little rubbing on my stock TJ with the stock Moab wheels. I think they look pretty good but they may not be tall enough for a lift.
 
With the tire size changes you posted above; you are going from a 32.8" to 30.6" tire.

1. Do you have an automatic or manual transmission?
2. Do you know what gear ratio is in the differentials; stock or upgraded?

IF the gearing has been previously upgraded already to offset the increase in tire size over stock; then when you drop 2+" in tire diameter the tires will be spinning 56.5 rpms faster per mile which means the engine will be put into a different operating power band at a given speed.
 
Do you have a lift or is it stock height?

What gear ratio do you have in it?

More info is needed. Help us help you.
 
JEEPCJTJ said:
Few if any tire salesmen here.

305/70R16s are pretty damn large. Does your TJ have a lift? What is the backspacing on your wheels?
do your tires rub on anything when turning all the way?

I'm running 235/85R16s on mine with no lift and very little rubbing on my stock TJ with the stock Moab wheels. I think they look pretty good but they may not be tall enough for a lift.
Click to expand...
Thanks for the reply. Yes, the 305's are very large and that is why i am downsizing. I really don't know the answer on
whether there is a lift or not. I assume there is or tires would not fit. I am a newbie so lots of learning ahead.

235's on your stock, no lift TJ, would be larger that what was originally on it. Specks say they came with 215-225' as
options. I am looking at 255's so even with a slight lift that should be plenty. Maybe larger is not what i need.
 
The way I am reading your posts, you seem to think the first number is mainly what makes a tire bigger or smaller but that’s not entirely true.

It is a combination of first number (tire width in millimeters NOT tire height), the second number (sidewall height as a ratio of width) and third number (rim diameter which adds up with the height of the sidewall second number)

So you can have a 215 tire that is taller than a 235 tire depending on the sidewall height and rim diameter but a 215 tire will always be narrower than a 235 tire since that number is strictly width.

Stock TJ SE is 215-75-15. Almost all TJs came with 15” wheels except for Rubicons and maybe a few special editions here and there. The widest tire that came on a TJ 245mm (Rubicon).
 
Last edited:
Vtx531 said:
The way I am reading your posts, you seem to think the first number is mainly what makes a tire bigger or smaller but that’s not entirely true.

It is a combination of first number (tire width in millimeters NOT tire height), the second number (sidewall height as a ratio of width) and third number (rim diameter which adds up with the height of the sidewall second number)

So you can have a 215 tire that is taller than a 235 tire depending on the sidewall height and rim diameter but a 215 tire will always be narrower than a 235 tire since that number is strictly height.

Stock TJ SE is 215-75-15. Almost all TJs came with 15” wheels except for Rubicons and maybe a few special editions here and there. The widest tire that came on a TJ 245mm (Rubicon).
Click to expand...
I have been educated about the #'s and their meanings. I am looking a set of 255/70R16's which are larger that stock
but way smaller that the 305's that are currently on now. I am assuming there is some sort of lift or the current tires
wouldn't fit. Am i on the right track with that size?
 
You are on the right track. That is sort of an odd size metric tire for a Jeep though. Are you set on keeping your 16” wheels? I think most would go with an equivalent 15” tire of 31x10.50R15 which would be the largest without any lift.

Either way, that size tire should look right with 0-2” lift.
 
Finally said:
I have been educated about the #'s and their meanings. I am looking a set of 255/70R16's which are larger that stock
but way smaller that the 305's that are currently on now. I am assuming there is some sort of lift or the current tires
wouldn't fit. Am i on the right track with that size?
Click to expand...
Measure the length of your springs and any spacer, but not the 1/2” isolator on top to determine how much lift you have. Front is 12” stock and rear is 8”. Anything over that is the amount of lift you have (e.g. 14” front and 10” rear would be 2“ lift). You must have this information to decide on proper tire size.

Also post some pics of your rig so we can see what it looks like with the 305’s on there. It would not be unheard of that someone put those size tires on a stock Jeep. 🙄
 
Finally said:
I have been educated about the #'s and their meanings. I am looking a set of 255/70R16's which are larger that stock
but way smaller that the 305's that are currently on now. I am assuming there is some sort of lift or the current tires
wouldn't fit. Am i on the right track with that size?
Click to expand...

30” wheel group available as an option on some models were 245/75R15 or 29.5” the tires you’re looking at are 30”. IMO if you have any lift at all it’s going to look stupid, I have the 30” wheel group on my bone stock 2005 and every time I sit and look at it I’m always thinking I need more rubber. Measure your front and rear spring at ride height and we can tell you what size lift you have if any.
 
245/75R16's are the stock tire on the Rubicons. I believe they are slightly larger than on a standard TJ. If you plan on staying on the pavement then stick with a 75 or 85 ratio. The thinner width will make highway driving easier. The wider the tire the more rolling resistance and if you aren't going offroad then there is no reason to need the extra flotation a wider tire gives.
 
Goatman said:
245/75R16's are the stock tire on the Rubicons. I believe they are slightly larger than on a standard TJ. If you plan on staying on the pavement then stick with a 75 or 85 ratio. The thinner width will make highway driving easier. The wider the tire the more rolling resistance and if you aren't going offroad then there is no reason to need the extra flotation a wider tire gives.
Click to expand...
But wider tires look better man!
 
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Do you plan to run it in the winter? As I'm sure you know, London gets its fair share of snow. If it helps, I have 245/75/16's on my TJ with no lift and 265/75/16's on my LJ with a 2" lift. My guess is that you have a higher lift if you're currently running 305's. I have Duratracs on both and run them throughout the winter for years. They go on sale at Canadian Tire about every 3 weeks.
 
CharlesHS said:
With the tire size changes you posted above; you are going from a 32.8" to 30.6" tire.

1. Do you have an automatic or manual transmission?
2. Do you know what gear ratio is in the differentials; stock or upgraded?

IF the gearing has been previously upgraded already to offset the increase in tire size over stock; then when you drop 2+" in tire diameter the tires will be spinning 56.5 rpms faster per mile which means the engine will be put into a different operating power band at a given speed.
Click to expand...
Manual...4.0l Sport I do NOT know the gear ratio as i just got it and already in storage out of town.
My guess is that previous owner just put on the larger tires and did not change the gearting
 
JMT said:
Measure the length of your springs and any spacer, but not the 1/2” isolator on top to determine how much lift you have. Front is 12” stock and rear is 8”. Anything over that is the amount of lift you have (e.g. 14” front and 10” rear would be 2“ lift). You must have this information to decide on proper tire size.

Also post some pics of your rig so we can see what it looks like with the 305’s on there. It would not be unheard of that someone put those size tires on a stock Jeep. 🙄
Click to expand...
I only had it for a few weeks before went into storage (Canadian winters). I am trying to gather as much information and
research before spring...i want to be prepared
 
Goatman said:
245/75R16's are the stock tire on the Rubicons. I believe they are slightly larger than on a standard TJ. If you plan on staying on the pavement then stick with a 75 or 85 ratio. The thinner width will make highway driving easier. The wider the tire the more rolling resistance and if you aren't going offroad then there is no reason to need the extra flotation a wider tire gives.
Click to expand...
I will be doing 80-90% road driving but looking for something that say Jeep, looks Jeep, but rides better than
off road mudders. So you are saying i should go with the 255/70 tires ?
 
Finally said:
Manual...4.0l Sport I do NOT know the gear ratio as i just got it and already in storage out of town.
My guess is that previous owner just put on the larger tires and did not change the gearting
Click to expand...
Figuring the previous owner did not upgrade the gearing; then your factory gearing is 3.07s.
The original tires were probably 215/75x15 that were 27.7", the present tires are 32.8" and the tires you are looking to go to are 30.6".
Your Jeep will feel sluggish when accelerating due to the wrong gearing for the tire size; to get the gearing to where it should be for that 32.8" tire you will need 4.11s and the 30.6" tire will require 3.73s.
 
CharlesHS said:
Figuring the previous owner did not upgrade the gearing; then your factory gearing is 3.07s.
The original tires were probably 215/75x15 that were 27.7", the present tires are 32.8" and the tires you are looking to go to are 30.6".
Your Jeep will feel sluggish when accelerating due to the wrong gearing for the tire size; to get the gearing to where it should be for that 32.8" tire you will need 4.11s and the 30.6" tire will require 3.73s.
Click to expand...

That may all be true but no matter what is there, the smaller the tire is than the 32.8" the less sluggish it will feel.
 
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