Talk Morgan Forums Community The Malvern Arms Wider Tyres

To follow on from a previous thread, I have a 2013 Plus 4 with 6 inch wide rims (wire wheels). The tyre size fitted from new is 195-60-15. The tyres are probably time expired by now and I’m thinking of replacing them with 205-60-15. Toyo CF2s sound okay and are available in the wider size at reasonable cost. I don’t have a problem with ground clearance and intend to stay with 60 profile tyres.

Any advice on the pros and cons on going wider would be much appreciated.
Bob.

Check the rolling diameter as it could effect the speedo reading

This should help on the speedo question. Tyre changes

2% increase in circumference so speedo will under read by that amount. A 205/55R15 would be closer to original having circumference just 1.3% less.

Sizes are the same, both 15” and 60 profile so there shouldn’t be any speedometer issues. What you need to do is check whether your wheels are capable of taking wider tyres so they sit correctly when fitted. Also check how much leeway you have for tyres sticking out past the wheelarch. I'll try and dig out a site that works it out for wheel/tyre size allowance.


Just did a google check and general info says up to 20mm wider is usually ok and adds about 5mm to how much the tyre sticks out. So, for a 6.5” rim 195 to 205 looks ok.
My plus 8 has standard Morgan alloy rims. 15x6.5xJ with 0.307 inset. It has 205x60x15 tyres.

Bob

At the risk of putting a dampener on your plans , I would advise trying to see if you can find someone else who has done this and trying their car for yourself.

Wider tyres may give more ultimate grip in the dry , but they are not necessarily a good thing , especially on a Morgan.

The +4 is nimble and chuckable, the wider tyres will possibly hang on for longer BUT when they go you will be travelling at higher speed and catching them will be that bit more tricky. I think it was Tim (Hamwich) who said you want to choose tyres which you can break traction at low speeds to have fun, and will be controllable when drifting at higher speeds. Wider tyres won't help in either respect.

The 205/60 x 15 is a standard size for the alloy wheeled +8 , and I think that it over-tyred, a +4 needs a narrower contact patch to maintain its handling.

Good point Andy. THuogh we don't get it often narrower tyres are also better in snow & ice.

One benefit will be that the tyre extends out further from the rim, so the wheel is better protected if you catch a curb.

It is all a matter of visual taste as well. And who likes wider tyres for this reason, why not.
But I personally think that the Plus 4 drives from the factory with tyres whose dimensions of all Trads are optically too small in diameter.
If it is allowed to say so, I would go the other way to get more ground clearance and a more classic look with the Plus 4. Not wider but higher with 195/65/15.
And if the tyres should stay "crisper" then I would stick to the original size 195/60/15 and choose a really good tyre. As others say, in the rain a wider tire is worse and in the dry it can make the threshold very small.

I am amazed every time how well my 4/4 drives with its narrow tyres. I have the impression that the rubber compound etc. in my car contributes more to the grip than the width of the tyre.

Bugger! Just realised you have a Plus4!
Standard rim smaller so my tyre/wheel dimensions aren’t suitable for your rims. I think 205 tyres would be pushing the limits for your rims but some advice says 205 would be ok.
Perhaps looking for tyre makes that are recommended by Plus4 owners is best route.
I went with Avon ZV7’s in that way.