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Re: TPMS accuracy

Posted: Mon Apr 15, 2019 4:37 pm
by NG1
Thank you everyone. This has been really helpful.

Re: TPMS accuracy

Posted: Sun Apr 21, 2019 5:11 am
by hydrolift
@NG1

I have the same "problem". Did you measure your tire pressure with your Draper gauge? Was the TPMS reading correct?

BR
/Olof

Re: TPMS accuracy

Posted: Sat Sep 14, 2019 9:33 pm
by Lusky
So here's a question. If forecourts aren't accurate should one allow for this? As an example my rears are supposed to be 2.1 bar. According to good old Sainsburys inflation machine (other supermarkets are avIlable) they are. However TPMS says they are only 2.0 bar. Therefore should the sainsburys inflator be set at 2.2 bar?

Re: TPMS accuracy

Posted: Sat Sep 14, 2019 10:45 pm
by Deleted User 3871
If you have any concerns its best to use a good quality tyre pressure gauge.

I have an older version of this that has served me very well for many years. https://www.halfords.com/workshop-tools/garage-equipment/tyre-inflators-pressure-gauges/halfords-led-digital-tyre-pressure-gauge

Lusky wrote: Sat Sep 14, 2019 9:33 pm So here's a question. If forecourts aren't accurate should one allow for this? As an example my rears are supposed to be 2.1 bar. According to good old Sainsburys inflation machine (other supermarkets are avIlable) they are. However TPMS says they are only 2.0 bar. Therefore should the sainsburys inflator be set at 2.2 bar?

Re: TPMS accuracy

Posted: Sun Sep 15, 2019 8:03 am
by Lusky
Daewar, I have seen several people suggesting this, good idea but seems like a lot of faffing. Its bad enough as it is topping up the tyres when there is a queue the length of China waiting to use the one solitary machine lol. What's the worst that could happen if i topped up to 2.2 bar in the hope it compensated and actually became 2.1 bar.

Re: TPMS accuracy

Posted: Sun Sep 15, 2019 8:11 am
by calnorth
I don't like most petrol forecourt places and surrounds. Certainly don't trust those air pumps. Just want to arrive...fill....out PDQ. Sticking coins in things is crap as well.

So I got the Vertex tyre pump 4 years back - Heavy Duty Mini Air Compressor 12v at about £50. Similar to the current Sealy type. The gauge on it is seriously inaccurate. About 4 to 5 psi high and always has been. The pump is good but screwing onto the schrader valve is awful. WD40 relieves it...a bit.

Also got the Michelin pocket digital pressure gauge for £10 and that and TPMS are in agreement. No need to pump and run...waiting for TPMS

Re: TPMS accuracy

Posted: Sun Sep 15, 2019 2:27 pm
by Deleted User 3871
Hi Lucky,

It's not so much about having a little to much or to little air, it's about knowing acuratly what the pressure is. From this point you can then decide how much your happy to run under or over pressure.

The great thing about putting in a bit to much air is that it's easy to reduce later on which is what I always do. I then use the pressure gauge to drop the pressure accordingly.

Your also meant to check tyre pressures cold. driving will warm your tyres up and potentially give you an inacurate pressure. This is where having your own pump becomes a win win. You can also use it for other things like pumping up a football etc.

[quqote=Lusky post_id=69747 time=1568534632 user_id=9576]
Daewar, I have seen several people suggesting this, good idea but seems like a lot of faffing. Its bad enough as it is topping up the tyres when there is a queue the length of China waiting to use the one solitary machine lol. What's the worst that could happen if i topped up to 2.2 bar in the hope it compensated and actually became 2.1 bar.
[/quote]

Re: TPMS accuracy

Posted: Sun Sep 15, 2019 3:11 pm
by MikeGC
Get a decent pressure gauge and a cheap foot pump (about £7 at Halfords) - it’s easy-peasy-lemon-squeezy

Re: TPMS accuracy

Posted: Sun Sep 15, 2019 6:56 pm
by Lusky
Hi Mike a foot pump ? Next you will be telling me to put pen to paper rather than send an email. Just want to rock up, top up and drive away lol. Will try 2.2 tomorrow and see what happens, can always let out some air (just like the missus)

Re: TPMS accuracy

Posted: Sun Sep 15, 2019 10:43 pm
by Noddy1875
Daewar wrote: Sun Sep 15, 2019 2:27 pm
Your also meant to check tyre pressures cold. driving will warm your tyres up and potentially give you an inacurate pressure.
This is precisely my concern with TPMS. If you put say, 33psi in when cold by the time your tyres are warm, the TPMS will then read 34 or 35psi.

So does this mean my tyres are overinflated ? Or should I put less in knowing it will increase when they get warm ?