Checking Tyre Pressure

[astroboy]

Leaving a nail or screw in your tyre raises the risk of irrepairably damaging the plies and cords. I think that's what happened to me - the screw or whatever worked into a 2cm wide gash on the inside, until it popped out. On the outside it was quite a normal hole. And it was only 6 days from my last Sunday morning pressure check. The tyre was a goner.

I don't think AAM can help in times of full deflation because you don't have a spare tyre to begin with. This will be the time when you will curse and swear why BMW has to pick RFT. Even the jack mount under our car is not helping because normal jack will crush the plastic support on the jack mount.

When I say leaving the nail stuck on the tyre is not meant as permanent solution or intentional. Not all object will damage the internal steel belt and of course, you may not be as lucky every time. Damage to the steel belt on the tyre rolling surface will result in "pregnancy" on the rolling surface and cause your wheel to vibrate. Only experience this once in my 20 years driving experience.. sorry not since WWII..

What I'm trying to say is you normally won't suffer immediate full deflation on conventional tubeless tyre. You can identify those deflation through frequent visual inspection or during refill. Once you notice u suffering losing pressure to one of the wheel, go straight to the tyre shop for inspection, rather than look for the nail and unplug it at the petrol kiosk, or dumber still, unplug it at the R&R on the highway in the middle of the night, with family members of old and young in the car, .. and ask yourself "What now?" when witnessing the air gushing out..

You didn't suggest Rachel to get the mobility kit? :wink:

 

[Schwepps]

".. and yes, you are now naked to nails and screws but fear not: ...as long as the screw/nail remain stuck on the tyre, it takes weeks to fully deflate your tubeless tyre", gives a different impression and implies that there's no harm in leaving it in.

Calling AAM would be to ask for a tow immediately. Frankly I don't think using a mobility kit by the roadside suits fair Rachel. More appropriate if she calls the yellow truck...or you...to come rescue the damsel in distress.

 

[astroboy]

I have countless nail punctures experiences and mostly, the tyre "survive". Yet, these are consider 2nd grade tyre after mending and they will never get the front seat ever, it will either become my rear tyre, if not the reserve seat a.k.a spare tyre.

And the best part is some of these puncture were so tiny that I can hardly notice any deflation until I saw the the object physically with my eye when I wash my car.

These are all for discussion only and the 325i don't have the luxury to rotate tyre even.. due to front/rear different size..

Remember I tried to rotate my tyre last weekend but found its a handful because there no spare tyre to temporary sit in during the rotation. Unless I have 2 jacks or jack the car up high enough until both front and rear wheel lifted, then I can swap the front and rear, one side at a time.. thinking of it make me tired.. went and watch G.I. Joe on Sunday which is more enjoying! Amazing movie, you have Transformer, Spiderman, Ironman, X-men, James Bond North Pole and underwater world with X-wing style dog fight both in the sky and sea all in one 2 hours movie! So damn cool! :top:

Oh yes, damsel in distress, send in the Joes! :wink:

 

[E46Fanatic]

Actually using the mobility kit is more suited for our E9x princess than changing out a tyre. But I think she's quite a rebel and likes to live life on the edge a little. The rush of driving on non RFTs without a spare or a mobility kit might be something she enjoys .

 

[astroboy]

Wow! U sounded like having a one night stand without rubber.. Yah! Rub in the resin injection process using the mobility kit for extra satisfaction..

No la... its easier to just make a phone call.. that's normally what a gentlemen would ask a lady to do.. :wink: .. and now she's having both Schwepps and my contact.. let see who she chooses and not fight here..

*keeping my finger crossed..*

 

[E46Fanatic]

Wow! U sounded like having a one night stand without rubber.. Yah! Rub in the resin injection process using the mobility kit for extra satisfaction..

No la... its easier to just make a phone call.. that's normally what a gentlemen would ask a lady to do.. :wink:

No la. What I was refering to was that she drives without the seatbelts. I found that quite amusing.

 

[Schwepps]

And she knows one of us will surely rush to her aid for a free BKT lunch or Hoegaarden tea.

Astro, why would you want to do the rotation yourself? Just a small tip to a tyreshop mechanic will get you a full hydraulic lift and pneumatic wrench swop done in minutes. And you would still be in time for your movie.

Agree with you though that once punctured, a tyre is compromised. I would have a mental block exceeding 140kmh if I knew I had a plugged tyre on my ride.

 

[astroboy]

... Astro, why would you want to do the rotation yourself? Just a small tip to a tyreshop mechanic will get you a full hydraulic lift and pneumatic wrench swop done in minutes. And you would still be in time for your movie. ...

Hehe... just to make sure, or try to make sure we are the biological father to our kids.. that's why must do it ourselves..

.. or why drive yourself, get a chauffeur..

I never trust mechanics because hearing too many horror stories of BMW driven until wheel came off! Scared..

 

[Schwepps]

Allo...he's changed thousands of tyres, you may have changed less than 10. You're more likely to cross the bolt thread and have the wheel roll off like Alonso in Hungary.

 

[astroboy]

Okay, I got this for our E90 darling.. :wink:

This is taken from an E46 (I think) can someone confirm? which is not on RFT... kerb weight and distribution pretty similar, so can use it as our E90 tyre pressure guide when convert to non-RFT tyres:

Warning! Ignore the 61psi which I don't know what the fcuk is that!.. Insane!

So base on this, I recommend Rachel to run 220/260 kpa*.. or 32/38 psi* :wink:

* Cool temperature

Seem's RFT pressure recommendation is lower.. my 225/45R17 RFT is recommended at 200/230 on my E90 but this non-RFT label on E46 is suggesting 220/260 kpa..

By the way, are suppose to load up the car with 4 passenger when doing the refill, as recommended by the label?

 

[Schwepps]

Warning! Ignore the 61psi which I don't know what the fcuk is that!.. Insane!

I believe it's the special small spare. You sure these are non-RFT pressures kah? 46psi for a non-RFT is too high.

 

[astroboy]

For the 18", it is always recommended to run the tyre with a little more air, to protect the rim. The above label I took from an American E46, I wonder if an Asian's E46 is using different tyre pressure due to the climate.. doubt so.

 

[Schwepps]

And you assume it's for non-RFTs? They were on RFTs long before us. You should check before recommending.

 

[astroboy]

And you assume it's for non-RFTs? They were on RFTs long before us. You should check before recommending.

Oooo ya ka? my bad.. Again.. Now u talk I luluk liam liam and listen.. :wink:

I just check and confirmed that the E46 330i has already been using RFT since 2003 !!

Wow! Thanks for shedding lights on my dark journey to automotive knowledge! :top:

Found an online user manual for the 1999 E46 323i and 328i for American production. The recommended tyre size only go up until 17" with recommended tyre pressure of:

4 passengers: Front 29psi (2.0kpa), Rear 33psi (2.3kpa)
5 passenger + luggage: Front 33psi (2.3kpa), Rear 41psi (2.8kpa)

.. and yes, the 61psi is meant for the Space-saver spare tyre..

Now I'm confuse... so 18" non-RFT on E90 should use what pressure le? I sure Rachel need to know..

 

[Juan Powerblow]

The ride on an overly pumped up RFT is bone shattering leh...

 

[astroboy]

The ride on an overly pumped up RFT is bone shattering leh...

I echo your feelings, I am on 230kpa/280kpa for my 225/45R17 and its bone shattering indeed! My less than 2 year old ride suddenly sounded like 10 year old lio with lots of shattering noise from everywhere and need to slow down to lessen the bumps and knocks..

Just an additional thought, now Rachel is not only naked to nails and screws, even her 18" rims are also vulnerable to the notorious Malaysian pot holes should they under inflate.. No more super thick RFT side wall to protect her rims..

 

[Schwepps]

Now I'm confuse... so 18" non-RFT on E90 should use what pressure le? I sure Rachel need to know..

Sorry Astroboy, I don't mean to sound condescending. :wink: It's just that I could tell those were RFT pressures. A lot of common normal tyres have a max pressure of only 44 or 45 psi. Overinflating normal tyres can have bad results.

I reckon Rachel can pump her tyres to 29/33 psi for normal city driving and 31/35 psi for high speed or spirited driving. I hope the shop gave her the right tyre sizes, as I only advised her on brands and models, not sizes.

 

[Schwepps]

No more super thick RFT side wall to protect her rims..

Sorry, but have to correct you again. Rims are more likely to be dented with RFTs than normal tyres, especially low profile RFTs. That's why both my rear rims are already dented.

And in case you'd like to know, RFTs have been around for a long time. They were patented in 1892 and were used by the Americans in WWII.

 

[astroboy]

No worries dude! Everytime u correct me, I learn new things. My learning stops the moment you stop correcting me..

Those pressure u recommended for Rachel sounds good. In fact the 31/35 doesn't sound "spirited" enough.. Can push 33/38..

I also noticed you people are running -1.3 rear camber (BMW recommendation) which is pretty aggressive to my standard. I'm only on -1.1 and I should be risking rear outer wear if I take corners aggressively often. I will check my rear tyre often and try to identify the wear pattern so can rectify the camber setting before too late.. Another risk I should face if my rear camber is less aggressive is over steer... got to be careful to never switch off those life saving DSC..

 

[racheltoh]

aiyo...just 1 post entry...so many replies..and so many words.........
so give me the bottom line

- tyre pressure 29/33 (front/back) psi? or should i call uncle manji for recommendation since my left back is with baby sit, trunk with baby stroller.
- no AAM, but will use "family" a/c. IN my past 16 yrs of driving, 3 times nailed. twice, i drove slower than a turtle n reached the nearest tyre shop to get it plastered. the other time, called the mechanic over.
- must always remember no spare tyre. So if i go outstation, i must remember AAM.

tyres i got:
225/40 - front
255/35 - back

question... can i change all 4 tyres to be of the same size? then i change 2 rims? let say i change the front tyres to be of the same of the back??

if u wanna know if i m a good driver...ask pcchuah...he had such a 'good appetite' during the charity event...