Hi I may be silly here for not finding the answer, I bought a MX5 1.5 Sport Nav + ,19 plate last Aug and had a look at the manual as I believe I should get a warning light if my tyre pressure is low , I haven’t had one yet but I have only driven 2800 miles .Tyre’s have always looked ok but I meant to get them checked but after New Year I had an Op so couldn’t drive and then lockdown happened , I can drive now but have only had it out twice to shop and as I have been doing most of shopping when out for walk and haven’t went to a garage yet but I think this will be my next outing hence I am asking ( haven’t put petrol in car since Jan! )
I’m sure they’ll be just fine, but maybe you have a neighbour or friend you could ask to check them for you - socially distancing yourself in the process of course 
Thanks I can take them to get them checked at the petrol station , I was used to doing this with my older cars as I didn’t have any luxuries with them , I was just wondering about the automatic notification I should get from the warning light , it may be that I haven’t had it because they are ok so I was looking for some expert advice
It is best to check your tyre pressures at least once a month no matter what tech. the car has. Your car has the Tyre Pressure Monitoring but it is really to tell you that there is a problem while driving and is not really a substitute for checking them regularly.
Hope this helps.
Thanks , I will get them checked, I may update after I have and let you know, its sound like I don’t check my tyres but my last car Mazda 2 had to get checked constantly because it was old and the alloys were old. I did think the pressure warning would let you know when they were low so I wont rely on this now.
Hi F,
The problem is they tend to rely on differences in pressure rather than actual individual pressures so if over time they all lose the same amount it is unlikely that you would get a warning.
There is no substitute for regular checks then you know what is going on.
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There are two basic principles in pressure monitoring. The first is wheels have actual pressure monitors inside the wheel which physically measures pressure in each wheel and transmits that data to the car which can display individual pressures and then give warnings. It is relatively expensive in manufacture and if one fails in service, and they can be damaged, then you will not be looking at a small bill to replace it. Frequently you also have to a set up operation to tell the car which wheel is where, although some newer systems will recalibrate automatically.
The other common method is to use the ABS sensor information to detect wheels speed variations, something they are doing anyway. If a tyre gets a puncture during driving then the tyre deflates and the smaller diameter means that wheel is rotating faster than the other three most of the time and the low pressure warning will trigger. Some will just put a general warning up but it can also point to the specific tyre. It obviously does not know the actual pressure and in the situation you describe of standing for a while, is all tyres bleed air equally it won’t know the difference.
You should be able to see a low pressure tyre though, so if one has got a nail in and is sitting at 18psi, you should be able to easily visually see this difference to the others at 29psi from a walk round.
I would not be overly worried about this, while it is possible air will have leaked since January, tyres and wheels, especially if not corroded, and I wouldn’t expect an ND car to have serious bead area issues at this time in it’s life, then even if the tyres have lost 5psi, which would be a lot, it still won’t be an issue just town driving and getting to the garage.
Whereabouts are you. I’m sure a fellow member would be willing to check them for you and be sensible enough to maintain social distancing.
Hi checked tyres a few weeks ago all at 28, manual said 29 so all good now, put petrol in for first time since Jan too, live in Loch Lomond Scotland so not been too far as not allowed yet if sticking to rules but not so many are by the amount of people about
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