Found this in the boot... what pressure to use?

[MX5noob]

Can anyone suggest the correct pressure for an MX-5?
There are no markings on the compressor which I found in the boot.
By my own convoluted and probably ignorant methodology, Im assuming around the 1.8 mark?
Any advice and edumacation gratefully received!

[Glug69]

Doesn't it say in the door jam?

[jimmytheone]

The handbook for my uk spec 1.8 on 185/60/14s or 195/50/15 is
180kPa = 1.8kgf/cm2 = 26psi front & rear
HTH!

[AW111]

Glug69 said:

Doesn't it say in the door jam?

That would be the easiest way


Google says around 29 psi / 200 kpa.

[littleredrooster]

Don't rely on the gauge of the compressor - they're not very accurate.

[MX5noob]

Glug69 said:

Doesn't it say in the door jam?

Nothing there

jimmytheone said:

The handbook for my uk spec 1.8 on 185/60/14s or 195/50/15 is
180kPa = 1.8kgf/cm2 = 26psi front & rear
HTH!

Google also said 26PSI for my year MX5.
I found a nearly identical machine, which had:
1) Same black guage
2) Additional red guage, with PSI markings
What I dont know is.... what are the markings on my guage. The markings on my guage are not PSI I dont think.

AW111 said:

That would be the easiest way
Google says around 29 psi / 200 kpa.

My machine has a /100kpa text.
Im the weakest link here, as Im not sure what that means nor what my guage is measuring, as "PSI" is not featured on my dial/guage.
What am I missing?

Thanks for the help.

[MX5noob]

littleredrooster said:

Don't rely on the gauge of the compressor - they're not very accurate.

I can cross check it with something else at some point.
Or invest in a pressure guage (...at some point )

[Oilchange]

100 kpa =1 Bar

1 Bar = 14.4 psi

so 28.8 for a tyre is ok, as mentioned earlier 29 psi so 200 kpa roughly.

So fill the tyre up to 2

[MX5noob]

I found this online. Its not mine.
Note the PSI guage in red.

My machine is very similar, but missing the PSI markings in red.
If you see 26PSI in red, its by the 1.8 marker in black.
Thats why I mentioned the 1.8 figure in my earlier post.

But not wanting to guess, as I dont have any red guage data to reference, Im still not sure how to calculate what 26 to 29 PSI is, on that black guage, on my unit (in the first photo above)

Here is the other unit I found online with the additional red PSI guage....

[AW111]

MX5noob said:

Glug69 said:

Doesn't it say in the door jam?

Nothing there

jimmytheone said:

The handbook for my uk spec 1.8 on 185/60/14s or 195/50/15 is
180kPa = 1.8kgf/cm2 = 26psi front & rear
HTH!

Google also said 26PSI for my year MX5.
I found a nearly identical machine, which had:
1) Same black guage
2) Additional red guage, with PSI markings
What I dont know is.... what are the markings on my guage. The markings on my guage are not PSI I dont think.

AW111 said:

That would be the easiest way
Google says around 29 psi / 200 kpa.

My machine has a /100kpa text.
Im the weakest link here, as Im not sure what that means nor what my guage is measuring, as "PSI" is not featured on my dial/guage.
What am I missing?

Thanks for the help.

The gauge reads in kPa * 100.

So 2 on the gauge is 200 kPa.

[MX5noob]

Oilchange said:

100 kpa =1 Bar

1 Bar = 14.4 psi

so 28.8 for a tyre is ok, as mentioned earlier 29 psi so 200 kpa roughly

Just seen this. We posted at the exact same moment.
Got it. So my reckoning of 1.8 was OK (for 26psi, which is what id found online and was also echoed here).
I went into brain freeze regarding what a bar was anyhow. Thanks for the help Oilchange, and everyone else.

[Oilchange]