30 AE Tyre Pressure

Technical Area Wheels, Tyres & Brakes
1

Hi everyone,

I was just wanting to ask what any other 30 AE owners (or indeed anyone else with low profiles) set their tyre pressure at. My TPMS light has come on and I’ve checked my tyres and they all appear to be 25psi. I thought perhaps this is a little low? Or maybe the light came on as a minus 6 temp confused the system.

Thanks

Dutchie

2

Pass the tyre pump (not the dutchie) on the left hand side and inflate all four to 29 PSI

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3

Agree 29psi all-round

4

I go 30 as they tend to settle a little bit lower than that.

25psi must surely have the car feeling a little sluggish?

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5

Ha ha, you must be of a certain age. I heard it many times in the 80’s now only about once a week! Great tune.

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6

Usually 29psi :+1:

7

I think the clue was in your mention of a minus 6 degrees temperature

Air pressure drops as temperatures fall. So if you inflated your tyres to the correct 29 psi when the temperature was 10 or 12 degrees C, they would give a lower reading when the temperature drops.

As a general rule of thumb, I gather a drop of 1 to 2 psi for each 10 degrees C temperature drop is pretty standard.

So if you pumped them up to 29 psi on a warmish day, the pressure reading could well drop to 25 psi on a cold January day when it is minus 6C outside.

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8

29psi all round on my AE30. TPMS has only triggered twice in 5 years, once for a nail slow puncture (which for once in a repairable place on the tyre), the second was again on a really cold morning.

9

Thanks all and I think Nick has the answer. As they were all 25/26psi and the car sadly lives outside this is possibly the case. Warmer weather tomorrow so I’ll take another reading.

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10
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11

1982, summer of. The MX5 was 7 years away. Jesus, I was 13. My kids get it said at school now, not as much though.

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12

Definitely more critical with low profile tyres. I had a similar problem, no warning lights but on the usual weekly check pressures were really down.

13

Hi

I retested them this morning and all still about 26psi and it was about 5 degrees so. I think I’ll put some air in. I’m just a little surprised that they have lost the same amount of air if they were at 29psi when I bought the car mid November.

The car is without doubt , when all factors are taken in to consideration, the best motor I have owned.

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