LR60-15 / GR60-15 to Modern-day equivalent tires

[4404ME]

My '72 RR has 15" Keystone Aluminum Turbine wheels with Goodyear GT tires, at the present. I'm going to replace them with different 17" or 18"s eventually, but right now, just going to buy new tires for these wheels. What I'd like to know.. what are the modern-day equivalent sizes to the LR60 and GR60 (the car has LR's on the rear, GR's on the front). I'm told the LR's are 275/60's in today's market. Is that correct? Also, what's today's GR60? If you could suggest specific brands and the tire model, I'd appreciate it! Thanks!

 

[MoparLeo]

The 275/60 tire size is based on a 15" diameter rim. The first number 275 is the measurement in millimeters of the tires cross section. The second number /60 is expressed as a percentage of the tires height % from the rim edge to the top of the tread.
No 17" or 18" passenger tires back then. I am surprised by your age that you didn't know that. The tire sizing changes happened in the Seventies.
https://www.tirerack.com/tires/tiretech/45_conversionchart.jsp

 

[69L48Z27]

LR and GR is what the 78 Lil Red Express used. Those trucks get 245/60’s in the front and 275/60’s out back.

 

[diesel_lv]

The 275/60 tire size is based on a 15" diameter rim. The first number 275 is the measurement in millimeters of the tires cross section. The second number /60 is expressed as a percentage of the tires height % from the rim edge to the top of the tread.
No 17" or 18" passenger tires back then. I am surprised by your age that you didn't know that. The tire sizing changes happened in the Seventies.
https://www.tirerack.com/tires/tiretech/45_conversionchart.jsp

The 275/60 is not based on "any" rim diameter. Regardless of whether it is a 15, 16, 17, or 22" rim. 275 will "Always" be 10.8"+- and the sidewall will always be 6.5". 6.5 + 6.5 = 13" then add the rim diameter for overall diameter.

 

[diesel_lv]

15's : 245/60r15 n 275/60r15
17's : 245/50r17 n 275/50r17
18's : 245/45r18 n 275/45r18
That will keep same width front n back and same diameter of 26.6" front n 28" rear. Pick your poison on tire brands.

 

[MoparLeo]

15" Keystone Aluminum Turbine wheels with Goodyear GT tires, at the present. I'm going to replace them with different 17" or 18"s eventually, but right now, just going to buy new tires for these wheels. What I'd like to know.. what are the modern-day equivalent sizes to the LR60 and GR60 (the car has LR's on the rear, GR's on the front). I'm told the LR's are 275/60's in today's market. Is that correct? Also, what's today's GR60?

A 275/60 15 is 3" shorter than a 275/60-18. You can't use the same section width and aspect ratio and then just plug in a rim diameter.
That was the point. The op asked about

 

[4404ME]

The 275/60 tire size is based on a 15" diameter rim. The first number 275 is the measurement in millimeters of the tires cross section. The second number /60 is expressed as a percentage of the tires height % from the rim edge to the top of the tread.
No 17" or 18" passenger tires back then. I am surprised by your age that you didn't know that. The tire sizing changes happened in the Seventies.
https://www.tirerack.com/tires/tiretech/45_conversionchart.jsp

Just going to ask, ML, what, in my post, suggested to you that I didn't know 17", 18" tires weren't available 'back then'? I said, I was going to 'replace' them eventually with the larger sizes. As for the explanation of widths and ratios, that was not my question. Comprehension? Thanks for your reply!

 

[4404ME]

15's : 245/60r15 n 275/60r15
17's : 245/50r17 n 275/50r17
18's : 245/45r18 n 275/45r18
That will keep same width front n back and same diameter of 26.6" front n 28" rear. Pick your poison on tire brands.

 

[4404ME]

Thank you for your reply, and for understanding the question! I appreciate it!

 

[4404ME]

LR and GR is what the 78 Lil Red Express used. Those trucks get 245/60’s in the front and 275/60’s out back.

Thank You! I appreciate the info!

 

[diesel_lv]

Just going to ask, ML, what, in my post, suggested to you that I didn't know 17", 18" tires weren't available 'back then'? I said, I was going to 'replace' them eventually with the larger sizes. As for the explanation of widths and ratios, that was not my question. Comprehension? Thanks for your reply!

I was going to say something about reading comprehension myself but have been blocked from a fuel injection sight for being mean.

 

[MoparLeo]

Again, those are 15" sizes. That was the point. Not the same in 16,17 or 18". To maintain diameter you must decrease aspect ratios when going with larger diameter wheels. Question I read was about LR50 275/60 15" tires and future change to 17 or 18" wheels. Again 275/60 15 will not interchange with a 275/60-18. Some people are not versed in the tire formulas, aspect ratios and how they relate to load capacity and overall diameter. Normally to maintain diameter you use plus sizing. This is a formula where to maintain the tire's total diameter while increasing rim diameter, the aspect ratio must go down. Example a 275/60-15 would be in an 18" rim size 275/45-18 as shown by another person.
This will be harder riding, more prone to damage and bent rims in real world street driving. Everything has a cost.

 

[4404ME]

Again, those are 15" sizes. That was the point. Not the same in 16,17 or 18". To maintain diameter you must decrease aspect ratios when going with larger diameter wheels. Question I read was about LR50 275/60 15" tires and future change to 17 or 18" wheels. Again 275/60 15 will not interchange with a 275/60-18. Some people are not versed in the tire formulas, aspect ratios and how they relate to load capacity and overall diameter. Normally to maintain diameter you use plus sizing. This is a formula where to maintain the tire's total diameter while increasing rim diameter, the aspect ratio must go down. Example a 275/60-15 would be in an 18" rim size 275/45-18 as shown by another person.
This will be harder riding, more prone to damage and bent rims in real world street driving. Everything has a cost.

Again, you didn’t understand my question, and if you closely read your reply, well, it makes MY point. Thanks!

 

[rlahaie]

I agree that tires with 45 cross section tires ride rough. I moved from 15" to 17" rims on two of my cars (to accommodate bigger brake rotors) and they ride much rougher than other cars of same make that I own with 60 series tires. The positive side is that turn in and overall cornering performance is much improved.........you choose.
Rolland

 

[NUgladiator96]

LR and GR is what the 78 Lil Red Express used. Those trucks get 245/60’s in the front and 275/60’s out back.

Drawing on this post. I would like to find a replacement pair of LR60/15 for my LRE. I have 3 matched Goodyear Eagle ST White Block, and 1 Goodyear GT Radial white outline letter. I am not interested in replacing my beautiful stock rims, so I would like a pair of 275/60 15 Goodyear Eagle ST White Block, so I have a spare. Does such a tire exist? And where does one recommend sourcing it from?

Western
Chrome five-slot disc road wheels (5) 15"x8"
GOODYEAR
Raised white outline letter radial tires (5) LR60x15
This did me no good... https://www.tirerack.com/tires/tiretech/45_conversionchart.jsp
and the link here was still jibberish, so as clearly as possible please advise.

 

[69L48Z27]

I haven’t seen any repops like the stock LRE tires. Closest thing is someone repops Goodyear’s for a late 70’s C3 Corvette.

And yes, never give up those wheels.

If your in Facebook join a group called NARLETO. The people with original parts are in that group.

 

[33 IMP]

I don't think they have made the Goodyear eagle st's for at least ten years. If you found some, a good chance they would be too old to use.
You might try Cooper cobras, or Mickey Thompson sportsman S/T.