Mixed summer/all season tyres allowed on car?

seatbeltnoob

I have 4 summer tyres on my car.
Fronts have 6mm thread (bought 2017)
Rears have 4mm.
I live in a flat so I can't rotate wheels and have a set in storage.
I want to make the switch to all seasons, I know they're not going to be the best in summer nor best in winter. But at least they're not going to be completely useless in one season.
Can I upgrade the tyres to all seasons per axle as and when the wear? Or will it be illegal/void insurance if I have summers at the fronts and all seasons at the rear? It seems like a complete waste to spend money replacing tyres with 6mm thread left on them.

Spinybif

Assuming it's a front wheel drive car tyres on front normally wear quicker so if you wait a bit, and leave 6mm tyres on front,  wear will even out and you can replace all 4 at once.  
I'd vote for Michelin cross climate.

AdrianC

No, it won't be illegal. No, it won't void your insurance. No, it won't be an MOT issue.

BTW, it's "tread", not "thread".

neilmcl

What car is it, and what part of the country do you live?

Unless there something wrong with the tyres I personally wouldn't change a set of rears with 4mm still on them, yes they're not going to be as good as a new pair of tyres in the wet for example but there's still enough life in them yet. Easily enough for you to get to a point where you'd consider changing all 4.

Petriix

4mm is well above the point of needing to change them. It's not that common for people in the UK to really require winter or even cross climate tyres, but it does depend on your location and the road conditions. I would run them much closer to the limit, otherwise you're just throwing money away.

Ectophile

You can have a different tyre on every corner if you like.

So long as you don't mix radial and cross ply tyres, and don't put directional tyres on the wrong way round, it's all prefectly legal and will pass an MOT.

nick74

Motoring laws in the UK don't acknowledge there being any such thing as 'summer', 'winter' or 'all-season' tyres so you are free to do whatever you like in that respect here. 

thegentleway

You can but it’s not a great idea. It’ll be fine for normal driving but in an emergency it can destabilise the car. If one axle still has plenty of tread left when you come to replace you can sell them on eBay. 

BrookBond

What your suggesting isn't illegal but it's not recommended. Having said that, running the better tread on the front also isn't recommended either.... Best tread, always to the rear - two reasons, one it's easier for a normally competent driver to recover a slide if the front tyres let go than it is if the rears let go. Second, rear tyres (on a fwd car) can last many years and will perish before the tread goes below the legal standard and become dangerous.
If you only get two all seasons, then the car will be imbalanced front to rear, one axle will have more grip than the other and easier to spin. You can run all seasons all year, I have done for several years now with no noticeable side effects (Michelin Cross Climates) on both 2wd and 4wd cars.

Its unfortunate that you have no storage as really, buying 4 tyres would be the best option.... Can you not sell the 4 that come off on faceache or fleabay? 

Flight3287462

We you won't be doing them this winter so........

As above switch front to back and vica versa and change them all when required, probably next winter.

seatbeltnoob

neilmcl said:

What car is it, and what part of the country do you live?

Unless there something wrong with the tyres I personally wouldn't change a set of rears with 4mm still on them, yes they're not going to be as good as a new pair of tyres in the wet for example but there's still enough life in them yet. Easily enough for you to get to a point where you'd consider changing all 4.

2003 focus in London. The tyre with 4mm tread is a bit older than the 6mm (it only has more tread because it was put on 3 years ago as opposed to the other one which was put on 7 years ago). I know some people change tyres quite often, I dont know how I managed to get so much life out of them. I drive the car around 10K miles a year - so it's no supermarket runs.
The nearside 4mm has 2 puncture repairs done on it, so I think on the next puncture it will require a replacement. I'd rather change it per axle than just replace that tyre alone. I would rather move to all seasons given my circumstances so it's good that I'm able to change to all seasons in stages, not require change all at once.