Reedweaver wrote: ↑Mon Mar 18, 2019 5:36 pm The price is absolutely ridiculous for the premium 185/80/15 tyres with a low load index.

Just by putting the work Sport or Classic in the title seems to give the OK to charge the earth. SP250 owners are getting fleeced just fill out the wheel arches!

I'm thinking of putting some commercial cargo van tyres on and to hell with the ride comfort!

185/80R15C
Load index 103/102
Speed rating R, 106mph

5x tyres fitted is £300...

You have already wasted money on incorrect tyres, if you go van route tyres it will be "good after bad".

The other issue with van tyres is that their wall ply is far higher than car tyres and this is what affects the handling + road manners. Additionally your car is extremely light compared to the weight of a van - that's why manufacturers make tyres for cars and make different ones for vans etc. As has been pointed out, you get what you pay for - I would urge you to go Blockley or Vredestein for your car.

Regards.

Richard.

I have opted down the route of a premium 185/65/15 88T tyre with new inner tubes/bands on my wires.

There's quite a gap between the wheel arches as you would imagine. I will replacing them next year, probably with the Vredestein 185/80 R15 91H like a lot of SP owners.

When you dont have a lot of cash to throw about, I made the choice of actually driving the car and enjoying it.

You cant really restore an SP on a budget though, but I am doing my best...

Guitarman1951 asked about tyre choice for his 250 saloon...

The Dart tyre examples are throwing a bit of a curved ball in this instance given that...

A 250 V8's kerb weight is approximately 3150lbs,
compared to the Dart's 2200lbs.

guitarman1951 wrote: ↑Sun Mar 17, 2019 5:31 pm Can I thank everyone for their help, I now understand the tyre sizes, crossply and radial, and I didn't know the original tyres where 80 profile/height.So the 185x65x15 which luckily, I only bought 2, will have to be replaced with 75 or 80 .

The OP thanked the forum and got his answer before the thread was hijacked. Apologies though, we should have started a new thread for the SP's...

There is a chart on the web which I can't find at present that gives the rolling circumference for all tyre sizes including cross ply, to get the right gearing you need to get as close to the original rolling circumference as possible. For the SP it is the 185/65-15 H or V which is the nearest equivalent to the Avon Turbospeed 5.90 rolling circumference 1950.9mm verses 1952mm for the 185/65.
Diameter 621mm /621.5mm Circumference1950.9mm/1952.5mm, Reading at 30mph 29.98mph with a change of 0.25 mm loss of wheel arch gap.
For the V8 250 Saloon 185/70R15 is the 6.40 x 15 equivalent. Circumference 2016.3mm/2010.6mm, Reading at 30mph 30.08mph, arch gap loss -0.9mm.
You can work out the sizes by converting the inch size ie 5.90" to mm
https://www.willtheyfit.com/index.php?w ... offset2=20

There can also be insurance issues if you fit tyres with a lower speed rating than the posted top speed of your car, even if you never get to speeds anywhere near the rating. Insurance companies are always looking for an excuse not to pay out.....

Kevin

I have just checked my cars handbook 1967 V8 to find that the cross ply size is 6.00/6.40 x 15 RS5 or optional 185 x 15 radial. The aspect ratio is not given but it would unlikely be 75 .
It is interesting to note that both 6.00 and 6.4 sizes of crossply are std fitment
Paul

Where no aspect ratio is quoted it is assumed that it equates to 80.

Regards.

Richard.

The first road car radial 70 aspect ratio tyre was fitted to the XJ6 only 80 aspect ratios tyres were available in the 60's and early 70's as I wanted 185/70 for the SP back then but weren't available though quite a few fitted the XJ6 205/70R15 in those days to the SP, as said before they were dirt cheap as rejects due to balance problems, Jaguar apparently specified the maximum weights needed to balance the wheel.
There was a low profile cross ply available in the middle 60's called the Goodyear Grand Prix which was much wider than the standard cross ply, due to the cost of Dunlop Racing tyres for the mini and shortage of used tyres, the Grand Prix was a reasonable replacement though its road holding on the track wasn't quite as good as the Dunlop but far better than anything else.

the commonly accepted standard size would be 185/80 X 15.. Vredestien are a popular and easy to find brand carried by most classic car tyre suppliers.. some budget minded people fit 165x 15 which is smaller than original.. many others seeking to save money, use larger than original..
195/70X 15 are readily available and will work ..if you go much above that size there will be issue's with heavy steering when parking and possible clearance issue with rear spats.. 205/70 x 15 (XJ6 size) are quite commonly used, but they are too big for the rims and wont perform optimally.. if you live in Germany you'd need 185/80 x 15 to pass TUV ..Holland may have similar restrictions too..
I found some 'budget' tires in USA in 185/80 x 15 sold under the 'sunful' brand which I order from 'pep boys'.. approx $50 each out the door.
The old bias ply tyres are best avoided in my experience.(5.90 - 6.00 and 6.40 x 15 being original) they have higher rolling resistance, tend to follow lines in the road and dont last very long..and squeal like a pig when the car is driven hard ... there is good reason they became obsolete by the 1970's..