Tyre advice

[Bam Bam]

Hello everyone,

We've had a thing this week where one tyre deflates itself from 37 to 30 PSI (1.9 bar) pretty quickly, then stays there.

Can't see any obvious issues so possibilities are: 1) an issue with the valve or 2) a really small hole that closes itself up once the tyre deflates to 30PSI.

If we do have to replace the tyre does anyone have any strong recommendations or warnings?

Bridgestone Turanza 6 £127.99
Goodyear Vector 4 Seasons G3 £139.99
Continental PremiumContact 7 £132.99
Michelin e.PRIMACY £154.99

The Michelin rates higher for efficiency.

We live in Oxfordshire so I don't think we need winter tyres.

Someone recommended I get the same brand as the opposite tyre.

I feel bad about the environmental impact of replacing a tyre with plenty of tread so I'm wondering if adding a little bit of that gunk would close up a hole.

Obviously I've got tonnes of marking and other work to do all weekend so this is a hassle I could have done without.

Any suggestsions/recommendations welcome

 

[Diggsy]

If the tread on the tyre is still good, take it to a local independent tyre specialist, and they’ll be able to find the issue and sort it for you, for around the £20 mark. That’s what I would do.

 

[fnegroni]

if you covered more than 1,500 miles with those tires you might need to replace both not just one.
As suggested above, see if they can plug it first.
If not, beware: most tyre shops and mechanics know very little about the issues faced by modern cars when fitted with two tires of different diameter even if the tyres are the same make and model.
Or they heard about it but they haven’t experienced it themselves or don’t care enough.
A sad truth.

 

[ReintjeWA]

In an ideal world all four tyres on your car would be the same, in a realistic world you should aim for the two tyres on the same axle to be the same. You won’t notice anything during normal driving, but every tyre manufacturer has their own mix of compounds and tread designs (although they all become more similar the more computers figure out what works best). This difference in tyre may present itself when the tyre is pushed to its limit, and so you may find that under emergency braking, one side behaves differently to the other.

In terms of wear in the other tyre, that is a bit open to debate. Technically you want both tyres to have the same overall diameter, otherwise it can slowly destroy your differential, but I don’t know enough about mechanics to say whether that is still the case in EVs, and if that is even the case at all on for instance your front axle? If you lease your car, it’ll be a choice for the lease company. If you own the car I would err on side of caution and swap both tyres on the axle when you need to replace the tyre.

Your environmental worries are admirable but should be subject to your safety. Assuming you are still on your factory tyres, and if the need arises to replace both tyres on the same axle, perhaps you can store your undamaged tyre in case you need to replace one on the other axle?

In response to what tyre you should get, it depends a lot on your style of driving. I prefer a softer compound tyre that wears more, but gives me more grip. Some people prefer a harder compound that lasts longer, and don’t require extra grip.

The brands you have provided are all solid tyres. If you want to spend less you could consider brands like Falken, Toyo, or Kumho. Very similar performance. If you are happy with these prices, then you can never go wrong with a Michelin. Conti would be my second choice, Bridgestone last. That is just because in my experience the Turanza don’t seem to last and don’t offer that much grip either, but of course this was on an older style of Turanza.

Lastly, a tyre that loses pressure like that definitely needs looking in to. Check google reviews and find yourself a reputable tyre shop, don’t always go for the cheapest, they may be making their money by cutting your corners. And don’t bother with dealerships or mechanics, a lot of them send your car off to a local tyre shop anyway. (At least here in Perth they do)

 

[Ian Key]

I agree with @Diggsy and also if you have a service plan check to see if puncture repairs are covered. I have and had one of my tyres repaired FOC

 

[Tight Git]

I had a similar issue a few years ago with one nearly new tyre that had a very slow puncture. Bought a bottle of bike tyre tubeless liquid sealant from Decathlon and put it in - never lost any air afterwards.

 

[ReintjeWA]

I had a similar issue a few years ago with one nearly new tyre that had a very slow puncture. Bought a bottle of bike tyre tubeless liquid sealant from Decathlon and put it in - never lost any air afterwards.

Just be aware many tyre sealants also deteriorate your tyres from the inside over time. Just because something works for a while, or works for someone else, doesn't mean it is a safe and sound solution.

 

[Bam Bam]

Thanks everyone for your input on this.

I'm sure others will face similar decisions in the future and so this thread might be useful.

I took the car to the only remaining tyre place in town and they found a nail in the inner wall so it is unrepairable.

They only had a budget tyre in stock but said they could get another one in for this afternoon. All I could remember off the top of my head was the Continental Contact 7 so I asked for that.

Nothing was mentioned about getting a matching one on the other side, but it would actually be cheaper to get a mobile trye fitting so I can consider doing that another time.

I had a similar issue a few years ago with one nearly new tyre that had a very slow puncture. Bought a bottle of bike tyre tubeless liquid sealant from Decathlon and put it in - never lost any air afterwards.

That's the Yorkshire way!

 

[Walks with Enzo]

Firstly, a good tyre depot should be able to diagnose the leaking air.
I'd only replace my tyres with a good brand of cross climates.
Don't just think of them as a "tyre for snowwy places" My last car had them, never had any issues from +30deg C to -10degC.
Just generally give better traction in the wet crappy weather we are blessed with in the UK.

 

[fnegroni]

Just be aware many tyre sealants also deteriorate your tyres from the inside over time. Just because something works for a while, or works for someone else, doesn't mean it is a safe and sound solution.

Bike tubeless sealants don’t.
Besides car tyres are butyl lined.

I would though wonder how much sealant was added as when it dries off it could cause an imbalance (depending on quantity)

 

[andi]

We've had a problem from new. Been told to monitor issue. Left rear tyre goes down. Then after being left it's back to correct pressure. Fed up of trying to get TPMS sorted at dealers. Will wait for tyres to wear out and replace TPMS with non MG parts.
MG4 22 plate Trophy.

 

[RetiredPope]

When replacing tyres, consider the wet grip and fuel efficiency. Generally better fuel efficiency leads to worse wet grip. In independent testing the difference between the best and worst tyre for wet grip was 46m stopping difference. Each grade of wet stopping distance equates to 2 car lengths in stopping distance. Have a listen to Sliced Bread - Tyres on iPlayer. Sliced Bread - Car Tyres - BBC Sounds

 

[andi]

The problem with EV tyres fitted to MGs is they wear out fast and don't grip.

 

[Steve class of 69]

January 23 trophy has just started reporting back left tyre pressure low
Strange coincidence
Put a couple of psi in and it goes away for a few weeks

 

[ReintjeWA]

M

January 23 trophy has just started reporting back left tyre pressure low
Strange coincidence
Put a couple of psi in and it goes away for a few weeks

Might be a slow leak. If it keeps happening, it'll be worth to have a tyre shop look into it.

 

[FrancisM]

When I picked up the MG4 the tyre pressures were low around 2.1, I pumped them to 2.6. Two months later they were around 2.3 but the temperature has dropped by 8 degrees. I will check them manually every month.

 

[AndyL61]

When I picked up the MG4 the tyre pressures were low around 2.1, I pumped them to 2.6. Two months later they were around 2.3 but the temperature has dropped by 8 degrees. I will check them manually every month.

Pressures always drop with time also and more dramatic is with colder temperatures so what you described is normal. You will probably have to put some more air in as the temperature drops more.

 

[Ian Key]

When I picked up the MG4 the tyre pressures were low around 2.1, I pumped them to 2.6. Two months later they were around 2.3 but the temperature has dropped by 8 degrees. I will check them manually every month.

And remember the pressures won't update until the car has been driven for a bit.

 

[Martinonline]

I was checking the status of my Trophy's tyres after receiving a low pressure reading of 2.3bar on a cold day which I ignored and it went away when I drove this car. However, today, I got the status, with a normal statement about type pressures, see photo 1:



But when I checked I found as per photo 2:



I checked with my gauge and yes it was at 1.6bar and there was a screw in the outside raised tread. Repair will have to wait until after Christmas.

I had no alarms and, obviously, the car thinks 1.6bar is ok but 2.3bar is not. Strange software, probably using 'equals' rather then 'less than' in the detection routine.

 

[andi]

We have had many false warnings. The cold weather really makes it worse. N/S/R is always playing up.