Tires

[DevilDog]

Per the Pirelli website, these tires are for: "P4™ Four Seasons Plus is an all season tire dedicated to coupes, sedans and minivans." I like coupe vs. van. Thanks Nigel......I appreciate and value all of your comments.

[NigelW]

You're welcome, just make sure you buy something that is safe, tyres are the only thing that connects you to the road.

[Jose]

would a 195/15 fit better than a 205/15 and not be as small as a 185/15 ?

[Glyn Ruck]

A 185/80 X 15 vs a 195/80 X 15. The 195 has a greater rolling circumference by approx 2.4%. A 195 will put slightly more rubber on the road. A 195 is a reasonably good fit for our narrow rims without distorting the tyre profile.

Here is a typical tyre calculator/comparator that you can play with that will give you approximate values of respective sizes & comparisons.

https://www.tacomaworld.com/tirecalc?ti ... -195-80r15

Values are approximate & vary slightly from tyre manufacturer to manufacturer.

A 205 tyre needs a minimum 6J rim to perform properly.

[cass3958]

Just remember that the 80 in 185/80/15 means 80% of the width being in this case 185. So the side wall will be 145 tall compared to 80% of a 195/80/15 being 156 tall.
The side wall heights would be for each tyre size,
185/70/15 the sidewall height will be 129.5 This is the standard size tyre for the S Type better known as 185/R/15.
185/80/15 the sidewall height will be 148
195/80/15 the sidewall height will be 156
195/70/15 the sidewall height will be 136.5
195/65/15 the sidewall height will be 126.75
205/70/15 the sidewall height will be 143.5
205/65/15 the sidewall height will be 133.25
205/60/15 the sidewall height will be 123
You would be better to get a 195/65/15 or a 205/65/15 to get the correct look of the tyre in the arch.
The other thing to think about is getting the correct circumference of tyre as this will effect your speedo setting and the ability to get a wider taller tyre in and out of the rear arch aperture when pulling it off the wheel nut studs or wire wheel hub.

[Glyn Ruck]

Indeed! The calculator clearly shows the effect of changing rolling circumference on speedo.

The standard tyre size for an S Type is actually a 185/80. (old rating approx 78 profile (aspect ratio) according to Michelin & marked today as 80 by some.)

Example: https://www.longstonetyres.co.uk/185hr1 ... xvs-p.html ~ scroll down for details.

A 205 is really too wide for our stock rims. You made an oops with the 195/65

The wire wheel hub makes getting wider tyres particularly difficult to get out of the rear arch. (even though the S Type has a narrower rear track when fitted with wire wheel hubs ~ Disc wheels = 4' 6 1/4" vs Wire = 4' 4 7/8")

[cass3958]

Knew it was between 70 and 80 but did not know it was closer to 80 (78) so thanks for that Glyn.

As previously stated I have 205/70/15s on wire wheels and I can get these in and out of the rear arches but only just on a hydraulic lift with the wheels hanging straight down. In the past I have really struggled to get the wheel and tyre out of the arch when I was jacking the car up just on one side. If you let the air out of the tyre they go on and off easily but you need to have a compressor handy to pump them back up again. Best to stick with 195 profiles in the future.

Also you have to get the right speed rating for your car as some 195/80 tyres are designed for vans and have the load capacity but not the speed rating required for our S Types which can technically reach speeds of up to 125 MPH. More information on speed ratings can be found at https://www.tirerack.com/tires/tiretech ... ?techid=35

With the speedo there will always be some discrepancy between a new tyre and a worn tyre in circumference which will alter the speed reading but manufactures allowed for that in making speedometers read 10% faster than you were actually going. Modern cars are more accurate but if in doubt there are apps for your smart phone which work on GPS and are very accurate so occasionally I run this app alongside my speedo to get an accurate reading of the speed I am actually doing compared with the speedo reading.

In the UK the Police allow for this 10% discrepancy as the speedo could be out either plus or minus by 10% by not prosecuting you for speeding unless you are going 10% plus two miles an hour than the speed limit. So 35 in a 30, 57 in a 50, 68 in a 60 and 79 in a 70mph zone. I was once caught at 80 on a 70 mile an hour dual carriageway by a camera with no discretion.

So for those of you who think just because the speedo in your S Type was reading 100 mph the other day on that quiet back road and you think the old girl still has it in her, think again you are probably only doing 90. Sorry!

[Glyn Ruck]

I think 205/70's look nice on our cars but hear you regards removing rears roadside with the standard jack.

At least with modern tyre carcass construction we don't have to put up with large inflation growth & growth with rising speed over desired spec.

My car has 20 year old General tyres fitted at present that I don't trust one bit at that age although new (just something to stand the car on). All I could get here at the time when 185R X 15 disappeared from our market for a while.

I will likely fit 185 VR 15 Michelin XVS or 185 HR 15 Michelin XVS-P now.

You are spot on that a lot of 195/80's are designed for Vans, Utes, Bakkies, light trucks by whatever name you know them & some 4X4's & simply don't have the speed rating. I'm going to have to do what my insurance company tells me to. They are quick to refute claims if wrong speed rating tyres are fitted to a car here.

[NigelW]

Rob, my speedo is bang on according to two satnavs I've used and verified by a traffic cop that nicked me for doing 83mph sometime back.

[cass3958]

Rob, my speedo is bang on according to two satnavs I've used and verified by a traffic cop that nicked me for doing 83mph sometime back.

When I was on traffic 18 years ago down here in Devon we used to set the alarm on the Laser speed guns at 90 mph for the motorways so anything under 90 we would let go. We were still busy all day stopping people doing 91 or more. To stop someone at 83 in a 70 zone, it would have had to be deep snow or thunder storm rain. The fastest speed I caught on the motorway was 141 mph from a Porsche 911 being driven by a 57 year old. Clocked him from a bridge over the motorway. Took me some time to wind him in from a standing start but he eventually saw the blue lights behind him and slowed down. His tyres had the correct speed rating as I recall.lol.