Ok so what am I missing?

The rear tires I have on my 2005 XJR are : Potenza M&S 255/40 R19 100W RE97OAS Pole Position E970 FZ which are Summer tires.

If I search for any tire that is 255/40 R19 rated as a PERFORMANCE tire, Summer or all season why would it possibly NOT fit?

I have Brembo brakes which I would think makes no diffeence whatsoever but had to check that off on one site.

Reason I ask is I have come up with 2 makes that I want to choose from and both have AA A traction ratings. Several sites say that they are not compatible with my car.

 

Sellers often don't know much about what their selling.

 

It's possibly because the owner's handbook gives 19" wheels (and 20") as having a Y speed rated tyre ? However, why a W rated tyre wouldn't suit is beyond me as that's what specified for the 18" and 17" wheel options.

 

Guess when in doubt, don't, is the safest answer.

 

Thanks for the responses guys.

One tire I am looking at has a "Y" rating and the other a "W" rating. Since the lower speed rating of "W" indicates max speed of 168 mph and the "Y" something like a max of 186 mph and my car is limited to 156 mph I could go with the lower "W" rating not that I will ever go near 156 mph! If I did I would not publicly say so!

If the price differential is low I will go with the "Y".

Still have not made up my mind.

 

Big time tire stores won't even sell you a tire that is not listed on their computers. Too many lawyers. They cited load ratings. Went to a jippo store, he had no problem with installing anything I wanted.

 

jackra_1

There is no reason I can see other than the site in question assumes that the wheels are the wrong width? My perspective is that the site may also assume a change to a smaller size wheel, therefore asking if you have larger Brembo brakes. I can attest that my 18inch wheels clear the Brembos on my 05 Super V8.

I have had great success buying tires at very low prices from Simple Tire. Shipping is always free. I took a change on a brand/model called ATTRUO /AZ850 255/40/ZR19 M&S 100Y XL AA 320 with a more summer like tread pattern. $422 for 5 tires delivered, they have worked well in summer, rain, and now cold.I don't drive it with the roads salted but they did fine in very light snow. They did need to be road force balanced to smooth out the ride and I've had them for 6,000 miles.

The other set I bought from Simple Tire are TOYO T1 Proxes Sport summer tire 255/45/R18 103Y XL AA A 240. These were $396 for 5. I bought a set of 18 inch rims because my original 19 inch are no all round so have some irritating vibration at 50-60mph. The 18 inch are ROUND and w the TOYO tires my car rides like a JAG is expected to ride - smooth with great cornering ability.

I've had both sets of tires up to 110mph for short periods and 100 for somewhat longer.But my car somehow wants to cruise the highway at 90, making it look easy all the while.

This is my experience. I got lucky with both sets of tires on the price. It seems ike Simple Tire has little specials now and then especially when the seasons change, and I bought both sets during one of those times. Both were bought before the "trade wars" began when perhaps things were cheaper.

I enjoy your posts. I hope this adds something for you.
Regards,
Mike D

 

Sorry - poor proofread -

I meant to say took a chance on the "off brand" ATTRUO AZ850. I am very suspicious of the Chinese tire brands but these have luckily worked very well.

Thanks

 

Mike. Very useful information.

I have taken a chance and ordered 2 tires thru Walmart. $102 each with free shipping. Strange thing is I did have to pay tax.

On some other tires thru Walmart there were no tax charges.

They get an excellent review as "ultra high performance all season tires".

We will see.

I wanted excellent grip in the wet as well as in the dry and these were rated only very slightly lower than top of the class tires as a comparison.

 

My XJ8 L will never see anything north of 90 mph, so I just buy well-rated all season tires, usually Hankook.

 

Same with most of us Boomer from Boston, most of the time, with the 90 mph part.

 

Just make sure the load rating is correct. Specs are specs. The speed rating is subject to interpretation with us. As we know our cars and driving habits better than most car owners. Not many of us will do 156 for sustained periods. Load rating is non-negotiable for me, as this could affect the tire at any speed. This was a huge issue for the almost 3 ton FFRR (Range Rover) my wife drives. Add full time 4x4, and that can heat up a tire fast.I hope my wife doesn't drive a 3 ton truck 158 mph for long "sustained periods." I don't even want to know, or ask.

 

GT Radial Champiro UHPAS Ultra High Performance All Season- 255/40ZR19 100Y XL

I ended up going with the above tire. My only misgiving at this point in time is that it does not have a great traction rating. However I feel it will be better on wet surfaces
than my previous tires.

I do have an LSD so maybe not too bad. We will see.

Mark you mentioned the Range Rover. I am surprised at how my NA Range Rover Sport can accelerate so fast being such a heavy vehicle. I do have a VAP tune but that probably only adds about 25 bhp.

I have never had a ticket in the Jag and have had cops pass me when I was doing quite a bit over the limit on the highway at night.

Not so in the Rover. 2 tickets within 2 months of owning it.