Tire Question

[Desh]

I guess that's the problem with all cars. Cars are designed to appeal to "new car buyers" and those people are at least %90 total moron. People who buy 2WD Honda Ridgelines and complain about fuel economy, etc. The people who have steered BMW away from "The Ultimate Driving Machine" and towards some of the most useless vehicles ever made. People who buy brand new Kias instead of a year old Toyota for the same price. Dodge Caliber owners. Vettes with automatic transmissions. Those jerks.

This paragraph is pure gold.

[esteban]

I have enjoyed this thread more than I should have.

And I loathe the topic.

[NightWolve]

I'll admit, I wasn't aware new cars included some form of tire pressure detection. That happens when you've owned the same car for 18 years. It seems counter-intuitive an idea to me to try to stick some kind of say lithium-powered transmitter in the rim between the tire and transmit the data for processing to some control panel display for the driver to see. But I guess it makes sense that it's accomplished by proximity/balance sensors elsewhere though that could never provide exact or even good PSI accuracy as a manual check with a pressure gauge could and is what led to ZeroGamer thinking there was a problem.

Anyway, I had a weird/dangerous experience not that long ago worth pointing out on the subject of the importance of checking your tires from time to time, at least visually! My brakes were going out and I had to keep pumping the pedal to achieve slow down as I was going to a MicroCenter store pretty far away from me in another city!

It was pretty WTF cause I had changed everything myself over the years, the brake lines/pipes, calipers, hoses, drum shoes, drum pistons, etc. and it worked fine for years, so I was pretty upset! The car pretty much runs on mostly AutoZone/AdvanceAuto parts!

So, I stopped the car in a parking lot before getting there, popped the hood and noticed I had full brake fluid which left me not really knowing what the hell was going on (was thinking maybe the booster was finally going bad maybe)...

Well, I got to my destination safely by going slow and pumping the pedal as mentioned, parked, got out and somebody saw my front passenger-side tire was extremely deflated so he pointed it out to me. I was like, "Oh, thanks, f--k, so maybe that's why?!?!" A gas station was across the street, so I refilled it there for some quarters because I didn't have my supply box which had my 12VDC car light/air compressor in it. Sure enough, brakes worked fine again, so WTF ??

I never heard of this behavior due to low tire pressure or practically a flat tire... Never happened again as I try to remember to do visual tire checks, but I don't trust the car like I used to... I'm tired of looking at the rust anyway, so I'll be looking for a new one in the near future and will likely switch to a manual transmission also.

[SignOfZeta]

I think there's more going on there than you're aware of. The only way I can see tire pressure affecting pedal feel is in an ABS event, when the disparate tire pressures confuse the ECU, made worse while turning. Otherwise...I'm pretty sure that's physically impossible.

[wilykat]

Tire pressure sensing is not necessarily just inside tires, some models have different ways of detecting soft tires.  On my Grand Prix, it uses rotation sensors to monitor wheel's rotation rate (part of ABS system) and when the computer detects one of the tire's rotation rate is off by about 25% or more from other tires, it trips low pressure warning.

It can be reset from the dash board such as when you have spare tire (which is smaller and rotates faster on axis) or something.

[SignOfZeta]

Yep. We've covered that at least twice in this thread.

[BlueBMW]

Originally automakers were using "indirect" sensing first.  That involved basically just using the wheel speed sensors of the ABS / traction control system to detect a variation in a specific tire.  If I understand it right though, regulations changed sometime in the mid 2000's to require that new vehicles have "direct" sensors after a certain production date.  I suspect all new cars have direct sensors now which are usually mounted to the valve stem or strapped to the center of the wheel (I think Ford does this).

[SignOfZeta]

No. No no no. Read the thread!

The earlier indirect versions were mainly luxery makes looking for a way to help you spend your money. They weren't legally required at all.

When they became the law they went with the systems with sensors.

Now the OEMs have convinced the man that the indirect ones are good enough so newer cars are back to this method.

My 92 Miata has no TMPS.
My 2013 Fit has TPMS sensors.
My 2014 Golf doesn't (virtual).

[BlueBMW]

That is fantastic news then!  I got out of the wrenching business in 2014 so if that's when the changes happened then that's why I missed it.  Direct sensors were always a pain.  They loved to break or lose connection or have their batteries die.  You name it.  Almost every car that came in had a line stating "TPMS light is on"

If they've gone back to indirect detection then that's great.  I wonder if they use indirect on run-flat tires though since they don't deform as much when flat.

[SignOfZeta]

Yeah, you clearly live in BMW world. Run flats are shit to start with and I wouldn't touch them.

But you have a point and I wouldn't be surprised, like I said, if BMW and Merc kept at sensors for that reason and others. They don't exactly have a history/ethic of scaling back tech bloat.

[BlueBMW]

It got so technical even I couldn't keep up with it all.  They way over-complicated every aspect of those cars (BMWs that is).  And they wonder why they cant find good technicians anymore.  Its because they've all gone to engineering school instead.

[SignOfZeta]

The deck is so stacked against the American auto technician, heavily favoring crooks. Outside of the very few unionized areas there is no guaranteed pay. They expect you to study all day and spend $2000 a year on tools but generally over-hire to reduce wait times for customers. Making $30 an hour is nice...but not when you stand around all week waiting for work to come in, eventually only banking 20 hours by Friday.

In Germany they have worker protections, four year degrees (which are free), and customers who didn't spend every last cent on their car payment. There the hugely over engineered German car makes sense. In the US it's like trying to get a X Wing fighter tuned up in Hazard County and only being able to find 9 guys to wash your windows.

BTW, I work in an engineering lab these days. You work 40 hours, you get paid 40 hours. If you work 45 the 5 are billed at overtime. You know, like everyone else. If this was more common in dealerships I don't think finding good techs would be hard. Finding good techs is hard because they are constantly changing jobs trying to find one that isn't a total f*cking.

[BlueBMW]

Most of the guys I worked with have either gotten out or are trying to get out.  Its interesting in the case of BMW though.  They actually sent out a survey for us asking us why turnover was high.  Overwhelmingly techs described their situation and the high level of dissatisfaction.   BMW's ultimate answer was to ramp up their "STEP" program which is basically an expensive BMW-centric technical school.  Dealers pay $10K and they get a "trained" tech within two weeks.  So rather than try and retain the talent they already had they just turned up the machine to churn out new techs.

Its sad too.  I really feel bad for a lot of these "STEP" students.  They spend a good 20 to 40K doing the school expecting to make 60k to 100k right out the gate.  It never happens that way.  They get to the dealer and maybe make 35K to 40K and most of that goes to buying tools in their first two years.  After two years they realize how f*cked up it is and then they're part of the crowd trying to get out.  Oh but wait, they're under a contract with the dealer to work there for three years or they have to pay back the dealer what they spent to get the tech.

Also, many of the STEP students come in thinking they know it all and can do it only to realize they have book knowledge but absolutely no mechanical aptitude.  Quite the shocker when they know how a car works in theory but cant figure out how to use a ratchet effectively.

But you are right.  The crooks are the ones who make it now.  Basically we had two types of technicians: part swappers and true techs.  The true techs were guys like me who could do everything be it diagnosis, rebuild, service, electrical etc.  The part swappers cant diagnose their way out of a paper bag with the bottom cut out of it but they can throw parts in a car super fast.  While they often guess and replace the wrong parts they tend to make the most money.  They turn tons of hours swapping out parts while the other guy is diagnosing some ridiculous electrical problem and barely making the time they're there.  At the end of the week, the crooked part swapper has 80 hours on the books and I have 35.  They make a few bucks less an hour than me but are making double my paycheck.  Add in "performance" bonuses etc and they really rake it in.

Right now I'm working at a laboratory as an engineering intern and the environment is so different is incredible.  I come in and do my job.  I report my own hours and basically manage myself.  The work gets done.

[SignOfZeta]

When I was on vacation in SF once I set up a job interview at a Honda dealership. The guy there explained how the unionized system worked and it sounded pretty good. Basically like any other similar profession, machinist, plumber whatever. "Installer" is actually a title. This is significant because there are actually guys who do the main diagnosis and delegate to the installers. I thought that was a pretty good system since, chances are, you'll have one or two guys that are way better at diagnosis than other guys anyway.

If I had every work order handed to me first and I just did diagnosis and then handed it off to the next guy I could make insane money. The standard hour for diagnosis is usually plenty, especially in a dealership situation where you have full accurate documentation. There are also modifiers for getting more than an hour. I once got paid 11 hours of straight time to diagnose a particularly crazy AC issue since I was going through the whole thing with the technician hotline guys. Similarly if the guy I handed it to did transmission swaps exclusively he could do really well also.

Also he told me that a few months earlier the guys went on strike and shut his shit down for a month. I like that shit a LOT. Where I worked the moral was so bad you couldn't even organize a company picnic let alone a picket line.

[esteban]

Picnic @picketline @hotlinebling @neverheardthesong @drake? @honda @tirepressure