This is a challenge.
The OEM tire is a 255/65R15. It has a load index of 106 and a V (149 mph) speed rating and a UTQG of 160. There is exactly one company that makes them and they are $486.29 a piece assuming I could find someone in the country that has them in stock. (I can't.)
In comprable sizes, I've narrowed it down to a 275/60R15. Practically the same diameter and about .8 inches wider. I don't want to go narrower, I'd rather damage a tire than a wheel. Nobody makes a remotely performance-oriented tire in this size.
The next option is to change the wheels to a 16 or 17" wheel I can get decent tires for. Except that's not really an option either. The lug pattern on this car is 5 x 155 with a 106 mm center bore. Not exactly common. Read that as nobody makes them. Wheels are running in the $1500-$1900 each range.
Part of me wants to spend the money and put the correct tires on the car, but $1900 in tires is painful. That part of me is worried that the 275/60R15 tires are going to be a squishy, mushy mess that will destroy what handling the car has.
I'm open to suggestions.
Does anyone have any experience with Firestones Firehawk Indy 500 SL A/S touring tires? I've run the regular Indy 500s on the G35 and liked them but the SL A/S is a completely different tire.
How about BFGs Radial T/A or Coopers Cobra GT? Are they as ill handling as I'm afraid they are?
I would hate to spend $900 on tires just to turn around and spend $1900 to get what I wanted.
Why would the 275s be a squishy mess?
That's a weird original fitment, 160TW and a load rating of 106! I can see why, but it's still weird.
What's the word on the street regarding deviating from the Avon? It's an odd fitment, yes, but what happens when you stray from that?
Can you get custom wheel adapters made? I'm not sure what the offset is on the stock wheels, can you tollerate the ~1" thickness of spacers and still get off the shelf 17-18's that would work? How big is the centerbore, can you get down to something like a 5x114.3 or 5x5?
Looks like a quick Google Returns US Wheel adapters will make custom ones in anything <205MM for $190 a pair ($400 a set). This would enable you to run something more common. Might end up in the $2000 outlay this time, but then you could run any rims/tires you want in the future.
Everything short of Nitto NT555 and Mickey Thompson's in th 275/60R15 is T or S speed rated. Hard pass.
You're looking at OE or a set of wheels. A set of wheels would look disappointing on a Bentley. So my vote is OE rubber.
No doubt $1900 for tires hurts your feelings but I am about to spend ~$1000 to put tires on my CRV, tire prices are way higher than they used to be. With the driving that the car is going to see they will probably last a decade. It may be best to spend the money, save the time and have the right look. It is "only" $900 more than you would spend to put good tires on anything else you own these days.
The V12 308 guy posted info for the shop in China that made his wheels. IIRC they were about $400 apiece.
In reply to Keith Tanner :
The only 275's I run near this size were not very crisp handling. Turn-in could be described as eventually. Granted they were on a 70s era truck and this was 30 years ago.
In reply to David S. Wallens:
Most of the Bentley crowd is either part of the factory tire only group, or round black and holds air group. The Rolls Royce tire for this chassis is a 235 and many seem to be going that route and running a truck tire. The people running the narrower tire don't seem to care about how the car drives. How the car drives is pretty important to me and the wider tire is one of the reasons I like the Turbo R over a RR sedan.
In reply to nocones:
Wheel adapters is a possibility. That may happen in the future, but for now, I would like to get a decent tire on the car. I'm pretty sure the tires that are on it are 10+ years old.
I don't know if places like Rotiform do anything suitably stately (not a word usually used to describe them), but I'm wondering whether that angle might be less horrifying that what you're looking at? A quick search also shows up a few shops doing lug pattern rearrangement, so perhaps if you found a less expensive set of wheels you could come out ahead there.
I think the upshot is that unless you're able to save a grand on tires every five years repeatedly and plan to do so for some time to come, finding a set of the OE style tires makes the most sense.
Call me silly, but I worry that a nearly-inch-oversize on width is going to make that elegant car look like someone at the Buy Here Pay Here wedged whatever was cheap onto it. I hate the look of a tire on a too-narrow wheel. Hell, there's a little of that going on with the tires that came with my F-250 and it bothers me even at the "nadir of aging Ford pickup, avec peeling clearcoat" level of elegance.
Toyman! said:
How the car drives is pretty important to me and the wider tire is one of the reasons I like the Turbo R over a RR sedan.
Based on that, I'm thinking the OE-size Avons might be the right answer here.
Now price Hoosiers for a Corvette. Bentley tires aren't so bad now, right? 
In reply to NY Nick :
You spend a good bit more on tires than I do, but I understand what you are saying and am leaning in that direction myself.
Unfortunately, I'm pretty frugal most of the time as well. If I can get 95% of the performance for 40% of the price that's the way I will go. I just don't want to end up with 30% of the performance for 40% of the price.
Also, everything you ask of that car–how it rides, how it handles, how it brakes–is dependent on its tires.
My 911 came on mud and snow tires. On the way home from fetching it, I stopped at Tire Rack.
In reply to David S. Wallens :
I have paid the purple crack prices before and the G35 was eating 2 sets of 275/35r18s RE71s a year when the engine popped, so yes $1900 every 3-4 years almost seems pretty reasonable.
Toyman! said:
In reply to Keith Tanner :
The only 275's I run near this size were not very crisp handling. Turn-in could be described as eventually. Granted they were on a 70s era truck and this was 30 years ago.
You're looking at the same sidewall height and some extra carcass width. The sidewall construction is going to be more important than that. So I wouldn't shy away from the size particularly. I would check to make sure you're not going to have any clearance problems before going too far down that road - they won't be a full 0.8" wider because the (relatively) narrower wheel will pull them in a bit, but you're still going to want to make sure you've got an easy 0.5" of clearance to each current sidewall at full bump and full lock and with some deflection.
Normally I would expect tires on a car like this to age out before they wear out, but 160TW and a big heavy powerful car would argue otherwise :)
Get the right tire. You only cry once.
It's easy to check the age of the tires on the car, it should be stamped right into the sidewall. If not, well, that tells you something as well.
In reply to Keith Tanner :
I haven't found anything that looks like a date code. There is no way they could be original with 124k on the car but they are certainly old.
You can get Michelin Pilot Sport 4Ses that are the right diameter if you go with 20 inch wheels :).
In reply to Toyman! :
See!
But, yeah, this might be a buy once/cry once thing.
Very happy to see that you got the car. Albers Motorcars caters to those cars. It's a longtime family business. Tell Greg I say hi.
In reply to David S. Wallens :
Thanks for that information. I'll be contacting them about the seat ECUs.
Mr_Asa
UltimaDork
9/22/22 1:47 p.m.
Toyman! said:
In reply to Keith Tanner :
I haven't found anything that looks like a date code. There is no way they could be original with 124k on the car but they are certainly old.
On some older tires I've found that they only put the date code on one side. Might be worth looking at if you haven't?
Keith Tanner said:
Why would the 275s be a squishy mess?
That's a weird original fitment, 160TW and a load rating of 106! I can see why, but it's still weird.
*raises hand*
The only street friendly 275/60-15s that I am aware of are "cosmetic" tires with condom-thin sidewalls and laughable UTQG numbers. I think my Radial T/As are 320/A/B.
They are round, hold air, look cool, and work well with suspensions engineered around donut shaped tires, which is their primary purpose in life.
In reply to Mr_Asa :
Indeed, the tires on my truck were mounted so they were all pointed inward.
Mr_Asa said:
Toyman! said:
In reply to Keith Tanner :
I haven't found anything that looks like a date code. There is no way they could be original with 124k on the car but they are certainly old.
On some older tires I've found that they only put the date code on one side. Might be worth looking at if you haven't?
I think that's the case for all tires, it's only on one sidewall. Probability says that there's a 75% chance at least one of them is visible (right?) but if you get unlucky they might all be on the inside. Should be a format like 34-15, which would be the 34th week of 2015.
If there's no date code anywhere, that means they're expired for sure.
In your purchase thread I remember wondering about tires and looking them up to be $400 each, if you can get them.
But, I also remember seeing a Bentley wearing aftermarket steels like Bassett Aeros. It looked really good. They custom drill those wheels. I can not find the picture now but adding some meatballs for that "purposeful look" would be cool too. Inspiration.
