TPM's and tire goo

[mcbeee]

This is for North american Zeds specificallybut it may include others (?).
What type of tire pressure monitors are on the E89? I have the 19" wheels and the RFT's are like riding on solid tires, ouch. :thumbsdown: I hope it's ABS based.

So, if I switch to non-rft's and carry a mobility kit will the tire goo screw up the TPM's ??? ( I had a mobility kit in the '05 M3 and it came with non-rft's )

 

[Smokin]

My 2007 coupe has the in-tire TPM. I don't see them changing that for North America in the E89. I wouldn't use goo on 'em, they're expensive!

That said, I'm loving my PS2 ZPs.

 

[Breaker]

I'm finding the 18" with RFT's fine. Better than my old Coupe. Maybe that's why you always seem to see the press cars with the 18" on (all the new Z4's in the UK on the tv tests seem to have the 18" on)! :wink:

I really like the look of the new Z4 with those 19" wheels and I was thinking of buying some for mine this year, but I don't want to do a form over function mod to it if it spoils the ride of the car.

I'll see if I can test one with them on from the dealer before I think of buying.

 

[Anonymous]

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[gannet]

The one I tested was also on 19s and was a million time better ride than mine with the 18s...

 

[MikeS]

Interesting, I have the 19" wheels and have always wondered why others keep complaining about the RFTs. :evil:

 

[Breaker]

I'm finding the 18" with RFT's fine. Better than my old Coupe. Maybe that's why you always seem to see the press cars with the 18" on (all the new Z4's in the UK on the tv tests seem to have the 18" on)! :wink:

I really like the look of the new Z4 with those 19" wheels and I was thinking of buying some for mine this year, but I don't want to do a form over function mod to it if it spoils the ride of the car.

I'll see if I can test one with them on from the dealer before I think of buying.

Most dealers cars I tested had the 19" on, even the Brochure car has 19" of various style's

Tested 2 cars back to back and did not notice the change from 18" to 19" I would go with the 19" every time

Yes but they are dealer cars. The ones that will have reams printed or talked about on TV all seemed to have come with the 18".

Don't get me wrong, I really like the 19" but it just made me wonder when I noticed the cars, say, on Top Gear/ 5th Gear and in mags like EVO, they had the 18".

 

[Breaker]

The one I tested was also on 19s and was a million time better ride than mine with the 18s...

That's down to the newer model's suspension. Mine is way better on 18" on the road than my old Z4 on 18"! :wink:

 

[gannet]

The one I tested was also on 19s and was a million time better ride than mine with the 18s...

That's down to the newer model's suspension. Mine is way better on 18" on the road than my old Z4 on 18"! :wink:

What I meant was that it wouldn't put me off going for 19s on the new one...

 

[AlanJ]

This is for North american Zeds specificallybut it may include others (?).
What type of tire pressure monitors are on the E89? I have the 19" wheels and the RFT's are like riding on solid tires, ouch. :thumbsdown: I hope it's ABS based.

So, if I switch to non-rft's and carry a mobility kit will the tire goo screw up the TPM's ??? ( I had a mobility kit in the '05 M3 and it came with non-rft's )

I'm guessing the TPM is ABS based and measures the comparative rolling circumference - quick call to local dealer should clarify.

 

[Andy]

only in europe on earlier Zeds, all NAS were in-wheel sensors, hence mcbeee's question for the e89

anyone know how these in-tyre sensors work? Assume they aren't linked by an electrical cable?

 

[Smokin]

No, they're not liked by electrical cable, they work on radio frequency of some sort.

Tire Rack has an article here

 

[WLH]

No, they're not liked by electrical cable, they work on radio frequency of some sort.

Exactly right they operate on 433MHz. According to both my dealer and a local tire dealer who I have known for years using the tire goo with TPMS sensors will likely fail the sensor and should be used when no other option is possible. In most cases you will have a slow leak so just fill with air from your compressor until you can get to some place that can do a proper repair.

 

[mcbeee]

I'm confused a little here. I looked at the link and I'm thinking there is a gadget bolted onto the inside of the rim, correct??

I've never seen my wheels without rubber so I'm not too sure.
In any case it seems that tire goo is not a good thing on the new Zeds.

 

[WLH]

I'm confused a little here. I looked at the link and I'm thinking there is a gadget bolted onto the inside of the rim, correct??

I've never seen my wheels without rubber so I'm not too sure.
In any case it seems that tire goo is not a good thing on the new Zeds.

It's part of the valve stem assembly...

Now here come the next ripoff.... :x
Some tire dealers are going to tell you that when you replace your tires you much purchase a rebuilt kit for as much as $75 each and will even tell you that without doing that the warranty on your new tire is void.... The rebuild kit actually cost less than $10 and takes only minutes to install if the tire has been removed. I've seen consumer complaints about this already.

 

[Smokin]

With our relatively quick tire wear, I'd think we could go 2 or 3 sets of tires before we have to rebuild. Same sensors as in larger sedans, right? They certainly go longer between tire changes than we do.

 

[WLH]

It is a BMW part and is therefor covered by the warranty of 4 yrs/50,000 miles so during that period of time I would not let any tire dealer touch it.

 

[mcbeee]

Good info, thanks.

How is it my M3 had a mobility kit, I'm assuming that in '05 the TPMS was via ABS ??

 

[sars]

I would be surprised to find one of the valve stem sensors in the wheel, it is far easier to compare wheel rotational speeds using the ABS monitors. My old E85 had the reset feature which would take a few minutes to correct itself indicating that it had to wait until it could match all the wheels, i.e. each wheel rpm is +/-% within the average of the four wheels, if one wheel rpm is suddenly higher by some predetermined % above the average it determines it has lost pressure, as it is now a smaller diameter and therefore has to rotate faster to keep up.

However as I haven't got my new Z4 I cannot say that this will be the same.

Sarah

 

[srhutch]

I would be surprised to find one of the valve stem sensors in the wheel, it is far easier to compare wheel rotational speeds using the ABS monitors. My old E85 had the reset feature which would take a few minutes to correct itself indicating that it had to wait until it could match all the wheels, i.e. each wheel rpm is +/-% within the average of the four wheels, if one wheel rpm is suddenly higher by some predetermined % above the average it determines it has lost pressure, as it is now a smaller diameter and therefore has to rotate faster to keep up.

However as I haven't got my new Z4 I cannot say that this will be the same.

Sarah

US spec Z4's (and probably most other cars) do not rely on ABS is in the UK and europe, they have a sensor in each wheel.