Are TMPS kits necessary with tire replacement?

The Bridgestone Dueler RFTs on my '11 X5 5.0i are due for replacement after 23K miles. I have 275/20 front and 315/20 rear. The rear treads have an even wear; however, the front tires, the wearing pattern is more "aggressive" on the outside. This wearing pattern became noticeable at 15K miles and an alignment service was done- the alignment, from my anecdotal observation, did NOT slow down the outside wear n tear on both front tires...I'm guessing 23K miles is the average life span for these HP RFTs?....
I'm replacing the original with another "original", Bridgestone Dueler RFTs. The tire shop recommends TPMS kits with the tire replacement?...how necessary is this on a new vehicle? I'm not loosing sleep over the TPMS kits' cost as I'm over they screwing up the TPMS system.
Oh yeah, the shop also recommends nitrogen?....the O2 filled tire has 80% nitrogen already, right?

The only reason to need a TPMS kit is if the shop has a track record of breaking TPMS sensors. That should be enough of a reason to find another shop. Ask the shop if they will give you an 80% discount on the nitrogen fill.

Unless the shop plans to dismount TPMS sensors for whatever reason, I see no need for a kit. Maybe - MAYBE - on a 3-4+ y.o. car it somewhat makes sense just cause it's cheap.

Re "nitrogen fil'", I can't believe in 2012 this scam is still around.

Costco "gives" the nitrogen for free with new tires

agreed- the N fill makes absolutely no sense, especially on passenger cars. The TMPS kit is only necessary if there is frequent fluctuation of tire psi...in my case, unremarkable; however, it seems like "cheapo" insurance though. its either 40 clams for the kits or 20 tall pikes. Btw, an indy shop will service the tire replacement. thanks!!!

Originally Posted by smyles

Unless the shop plans to dismount TPMS sensors for whatever reason, I see no need for a kit. Maybe - MAYBE - on a 3-4+ y.o. car it somewhat makes sense just cause it's cheap.

Re "nitrogen fil'", I can't believe in 2012 this scam is still around.

do you notice any uneven tread wear patterns with your front tires?

What toe are you running on the fronts? Outer wear is almost unavoidable give the tire size, weight in the front and inability to rotate.

Nitrogen is a scam...unless you are using 99.9% technical pure, certified moisture free BOTTLED nitrogen, it isn;t doing a damn thing. Green valve stem covers simply advertise stupid...

A

Originally Posted by ard

What toe are you running on the fronts? Outer wear is almost unavoidable give the tire size, weight in the front and inability to rotate.

Nitrogen is a scam...unless you are using 99.9% technical pure, certified moisture free BOTTLED nitrogen, it isn;t doing a damn thing. Green valve stem covers simply advertise stupid...

A

alright...mr. bmw has spoken....i'll try to retrieve the results from the last alignment on the toe. the tech also mentioned the weight in front as a factor- i thought the SAV has almost 50/50 weight raito?....btw, 20K-25K miles would be the average life span of these H/P RFTs?

Originally Posted by ard

What toe are you running on the fronts? Outer wear is almost unavoidable give the tire size, weight in the front and inability to rotate.

Nitrogen is a scam...unless you are using 99.9% technical pure, certified moisture free BOTTLED nitrogen, it isn;t doing a damn thing. Green valve stem covers simply advertise stupid...

A

before:
rear axle
toe left 0 degree 02'
toe right 0 degree 06'
camber left -0 degree 58'
camber rigth -1 degree 15'

front axle
toe left 0 12'
toe right 0 09'
camber left -0 08'
camber right -0 18'

after:
rear axle
toe left 0 04'
toe right 0 05'

front axle
toe left 0 05'
toe right 0 05'

Wear on the outside edges isn't caused so much by toe or camber, as by cornering, With the weight of your X5, it takes a lot of force to change direction, all of which is being transmitted through your front tires and thier slip angles. If you lived in Wyoming and drove arrow straight for hundreds of miles at a time, you'd see much less wear. If you ran the Tail of the Dragon every week, did HPDE's or autocrosses, you see accelerated wear.

If it makes you feel any better, 23,000 miles is pretty darn good. I wish my Dunlops would wear that long. Did you consider going to a non-RFT like the Conti DWS's? Much nicer ride, and a significant savings. Lower weight will result in less unsprung mass and less rotational inertia, which will improve the handling when you do run the Tail of the Dragon.

BTW I'd spring for the TPMS rebuild kits. YMMV

Originally Posted by quackbury

Wear on the outside edges isn't caused so much by toe or camber, as by cornering, With the weight of your X5, it takes a lot of force to change direction, all of which is being transmitted through your front tires and thier slip angles. If you lived in Wyoming and drove arrow straight for hundreds of miles at a time, you'd see much less wear. If you ran the Tail of the Dragon every week, did HPDE's or autocrosses, you see accelerated wear.

If it makes you feel any better, 23,000 miles is pretty darn good. I wish my Dunlops would wear that long. Did you consider going to a non-RFT like the Conti DWS's? Much nicer ride, and a significant savings. Lower weight will result in less unsprung mass and less rotational inertia, which will improve the handling when you do run the Tail of the Dragon.

BTW I'd spring for the TPMS rebuild kits. YMMV

conti dws would be a more practical option in this region...but, the idea of treading on non-rfts doesn't secure a sense of perceived assurance while transporting young ducklings.

Originally Posted by caden

conti dws would be a more practical option in this region...but, the idea of treading on non-rfts doesn't secure a sense of perceived assurance while transporting young ducklings.

Like Mark Twain's demise, the added security conferred by RFT's has been vastly overrated. According to your X5 Owner's Manual, a deflated RFT can be driven as speeds below 50 mph for no more than 30 miles (4 passengers, plus luggage) to 95 miles (4 passengers, no luggage). And once you drive on a deflated RFT, it is toast - it must be replaced (and the 20" rear Dunlops cost +/- $650 per tire).

If your RFT goes flat on the Beltway, you may be able to get home okay. But if you are on a family vacation to the Outer Banks you are SOL. And what do you think the odds are of finding a 20" RFT on a Sunday in OBX? In that scenario, you'd be far better served by the Conti's.

IMHO the ONLY reason a RFT might be better than a non-RFT would be in the event of a catastrophic blow out, where the RFT would give you marginally better maneuverability. (But having driven on a blown-out RFT, I can tell you it is anything but confidence inspiring. Consider that most blow outs happen because of underinflation, and that you have to be a world class knucklehead to ignore the TPMS, and I think the whole RFT deal is a load of hogwash, invented to allow manufactureres to bypass the expense and space considerations of providing a spare.

My 2 cents. YMMV.

Originally Posted by quackbury

Like Mark Twain's demise, the added security conferred by RFT's has been vastly overrated. According to your X5 Owner's Manual, a deflated RFT can be driven as speeds below 50 mph for no more than 30 miles (4 passengers, plus luggage) to 95 miles (4 passengers, no luggage). And once you drive on a deflated RFT, it is toast - it must be replaced (and the 20" rear Dunlops cost +/- $650 per tire).

If your RFT goes flat on the Beltway, you may be able to get home okay. But if you are on a family vacation to the Outer Banks you are SOL. And what do you think the odds are of finding a 20" RFT on a Sunday in OBX? In that scenario, you'd be far better served by the Conti's.

IMHO the ONLY reason a RFT might be better than a non-RFT would be in the event of a catastrophic blow out, where the RFT would give you marginally better maneuverability. (But having driven on a blown-out RFT, I can tell you it is anything but confidence inspiring. Consider that most blow outs happen because of underinflation, and that you have to be a world class knucklehead to ignore the TPMS, and I think the whole RFT deal is a load of hogwash, invented to allow manufactureres to bypass the expense and space considerations of providing a spare.

My 2 cents. YMMV.

true that- well said! getting a flat isn't exactly an "average" experience...I've been served by the coorperation.....

I agree with the above. When I'm due for a new set, I'm going to ditch the RFT's and go with the Conti DWS. I drank the Conti extreme DW coolaid with my E46 M3 and was much happier once I did. I don't even think I'd carry a spare, probably just buy an M-mobility kit and throw it in the back along with a plug kit.

I have 28,700 miles on my Dunlops. I am replacing them next week with the Conti's. And I have the spare!

The only reason they use nitrogen is because air has water in its makeup. The water will eventually effect the TPMS over a period of time. If nitrogen has been used within the tire before their is no reason for replacement of the monitors. Basically its you call regarding comfort level.

I agree completely with quackbury, my only experience with RFT was with my 2011 corvette. I had a major puncture, over 1/4 inch hole which was UN-repairable. I drove the car for over 20 miles before reaching Discount Tires, whom I had road hazard insurance, and the replacement cost to me was $48.00 for a $700.00 tire. With respect to RFT, I elected to by the emergency spare with associated tray, jack ...etc. The thought of being stranded was not appealing. If one is incapable of changing a tire this may not be necessary since the tow truck will take to to a dealership. I do recommend the road hazard insurance but forget the wheel locks. When they steel BMW they have a tow truck and they just take the whole vehicle.

Originally Posted by Pourboire

The only reason they use nitrogen is because air has water in its makeup. The water will eventually effect the TPMS over a period of time. If nitrogen has been used within the tire before their is no reason for replacement of the monitors. Basically its you call regarding comfort level.

What makes you think the crappy nitrogen concentrators that make 93% nitrogen dont also have water contamination.

Fears about sensor damage if you dont use nitrogen are just part of the scam around up-selling N2 fills.

1st the rebuild kits are the stems that the TPS is mounted to. Moisture tends to cause issues to the valves so the couple dollars is not that much to have a better chance of no leaks from the valve. As for nitrogen, it is a Scam. Don't worry about the "water" or other types of air which are in the tires. You will never reap the benefits that Nitrogen provides.

Originally Posted by ard

Fears about sensor damage if you dont use nitrogen are just part of the scam around up-selling N2 fills.

Yep, especially considering they are sealed plastic boxes.

First and foremost if it is a dedicated system, nitrogen can't hold water. If its injecting the right percentage of air, this is the only source of water. Did you ever wonder why your barbeque (if you have a propane one) has rust on the burners. You got it, propane is full of water. Having been a system engineer for over 40 years, and addressing issues like the aforementioned, this is just basic knowledge. How do you know the shop is really replacing your oil filter (no matter the make of car). In my case i was suspicious that the dealer (Lexus) wasn't replacing my oil filter when the oil was changed. This lead me to putting tape on the filter with the present date when I brought it in for service. When finished with the service, I opened the hood and guess what. You got it. Their got to be some element of trust, how you can determine this is not an easy.

Originally Posted by Pourboire

First and foremost if it is a dedicated system, nitrogen can't hold water. If its injecting the right percentage of air, this is the only source of water. Did you ever wonder why your barbeque (if you have a propane one) has rust on the burners. You got it, propane is full of water. Having been a system engineer for over 40 years, and addressing issues like the aforementioned, this is just basic knowledge. How do you know the shop is really replacing your oil filter (no matter the make of car). In my case i was suspicious that the dealer (Lexus) wasn't replacing my oil filter when the oil was changed. This lead me to putting tape on the filter with the present date when I brought it in for service. When finished with the service, I opened the hood and guess what. You got it. Their got to be some element of trust, how you can determine this is not an easy.

40 years as a "system engineer" ??...

Why don't you explain to the unwashed masses how nitrogen generated from a nitrogen concentrator (ie ~94% pure nitrogen) CANNOT "hold moisture"? Please don't confuse this with bottled nitrogen.( which can be 99.99+% pure)

The issue is not 'nitrogen'...the issue is what tire stores and car dealers are selling as "Nitrogen Fill"....

Pure and simple it will dissolve in water

General information.

There are several compelling reasons to use pure nitrogen in tires.

First is that nitrogen is less likely to migrate through tire rubber than is oxygen, which means that your tire pressures will remain more stable over the long term. Racers figured out pretty quickly that tires filled with nitrogen rather than air also exhibit less pressure change with temperature swings. That means more consistent inflation pressures during a race as the tires heat up. And when you're tweaking a race car's handling with half-psi changes, that's important.

Passenger cars can also benefit from the more stable pressures. But there's more: Humidity (water) is a Bad Thing to have inside a tire. Water, present as a vapor or even as a liquid in a tire, causes more of a pressure change with temperature swings than dry air does. It also promotes corrosion of the steel or aluminum rim.

If I ever need to top off a tire when I'm out on the road, I'll always briefly depress the tire chuck's valve with my thumbnail and vent some air. If my thumb gets wet, there's water in the line. Some gas stations don't do a very good job of keeping the humidity out of their air system. I don't even like to use a water-based tire-mounting lubricant unless I can let the tire bake in the sun for a couple of hours before I air it up and seat the bead. I've dismounted tires (not mine) that had several quarts of water inside—probably from a compressed-air hose that collected water and was never purged properly.

How is water relevant to a nitrogen discussion? Any system that delivers pure nitrogen is also going to deliver dry nitrogen. Filling tires with nitrogen involves filling and purging several times in succession, serially diluting the concentration of oxygen in the tire. This will also remove any water.

It's certainly simple, although time-consuming, for a tire technician to fill and bleed tires. But most shops use a machine that not only generates almost pure nitrogen by straining the oxygen out of shop-compressed air, but will also automatically go through several purge cycles unattended. Some shops have been charging as much as $30 per tire for this service. I think that's too much. If you're buying a new tire, it should be far less. Still, the nitrogen generator, filling system and technician's time aren't free—the dealer is entitled to some return for that.

So, to answer your specific questions: With nitrogen, your tire pressures will remain more constant, saving you a small amount in fuel and tire-maintenance costs. There will be less moisture inside your tires, meaning less corrosion on your wheels. You will not be able to feel any difference in the ride or handling or braking, unless your tire pressures were seriously out of spec and changing to nitrogen brought them back to the proper number

Originally Posted by Pourboire

Pure and simple it will dissolve in water

Huh? That is why water vapor cannot exist in an N2 atmosphere???

Question was other way around...how do we know there isn't moisture in the Nitrogen concentrators that are 6% regular air?

It is important, for a critical thinker, to separate the hype of sales from the practical real world application of this 'less than pure nitrogen' fill.

Don't hype "pure nitrogen" when that is simply NOT WHAT IS BEING SOLD IN TIRE STORES. Again, look up what these tire stores are selling. AFAIK, no membrane concentrator is over 94%.

All the 'race cars use it' and 'airplanes use it' stories do not apply. Your assertion that Nitrogen has less pressure fluctuation due to temperature changes is utter fallacy- PV=nRT. AS a system engineer you must knot that all gasses obey this law, right?

Back to reality... you seem to be buying this 'pure, dry nitrogen' myth. Nobody sells pure nitrogen, ergo- by you own logic- there IS moisture in the 94% N2 fill since it is 6% air (really other air components)

We agree moisture is bad... so use dry air. But 94% nitrogen is no better than 78% nitrogen we get for free.

(I'll bet this is where you change the argument to "well, it may not be pure, but they PROBABLY do a better job with moisture")

A

PS "Several quarts of water'??