Aftermarket TPMS (Tire Presure Monitoring System)

If you are atuned to the feel of your Ferrari, you can feel when the air pressures are off by as little as 1 PSI. This same level of atunedness can detect 2 PSI in something like a Vette, 3 PSI in a Mustang, and 5 PSI in something like a typical SUV.

So, in my opinion, these thigns are good for inattentive drivers, and for cars where it pretty does not mater how much air is in the tires. Somehow Ferraris don't fit that matrix.

 

feel the difference of 1psi?! Something about a Princess and a pea comes to mind...

Last year I bought the Orange system from the Tire Rack pre-installed (at no charge) on a set of cheap rims and snow tires for winter duty on my fiancee BMW 528. I see now that TR doesn't sell the Orange unit anymore, but still has the more expensive (but functionally equal from what I understand) Hella system
http://www.tirerack.com/accessories/detail.jsp?ID=51)

I think these are a great idea, especially in the winter when it's no fun checking the pressure regularly and the ramifications of a flat tire are much different than the summer.

Would love to have them on my Grand Cherokee since if the pressures are not very close on all 4 tires the 4WD viscous coupler quickly destroys itself, but I check these at least every week the old fashioned way.

It's also interesting to check the t and p when you start a drive, then watch them climb as the tires heat up. Can set an alarm for low/high pressure or temp also which is nice.

This place looks to have the Orange system, but you're on your own getting them installed

http://www.vulcantire.com/orange_409_sys.htm?refad=Froogle11090&kw=%7Bkeyword%7D

The batteries in the transmitters are supposedly good for 7 years. Our worked flaslessly all winter last year, and so far after putting them on a few weeks ago still read true.

Kurt

 

Here's another external type system to check out: http://www.pressureprosystem.com/catalog.html - made in America. Haven't tried any of them myself, considering installing one on my RV.

With the PresssurePro system, if you have rubber valve stems, they should be replaced with metal ones due to the forces generated by the pressure sensors per PressurePro FAQs. Perhaps metal valve stems are required for most external sensor systems. That makes the external system a lot less convenient for installation (tire dismounting required), plus the sensors are exposed to the elements constantly. Otoh, when the sensor batteries go dead they are easy to renew compared to the internal type sensors.

I guess the ideal system would be an internal system that the sensor batteries can be recharged from outside the tire when they get low. Sounds like a nice improvement for internal systems, maybe it exists.....?

 

I like that they work on trailers too. On multi axle trailers a lot of times you don't know the tires low on air till you see the sparks from the rim hitting the road in the rear view mirror. On a small trailer one time I didn't know till I slowed down that the tire had blown out.

 

They do make a locking device for the sensors, don't know how effective it realistically is.