Saving on vehicle costs

[EllisWyatt]

Lake Travis -
I have no idea why the brakes (and a whole lot of other compenants as well) have lasted as long as they have in this vehicle. A couple of hypotheses -1) most of the driving has been highway driving in flatlands (very little stop and go, very few mountains), 2) the entire brake system of this model of Suburban was significantly upgraded from tthe previous model (my '91 Suburban went through brakes like butter and one occaision overheated so badly that the brakes locked up and caught the brake fluid on fire. Scary), 3) even though I got the trailering package, I seldom pulled a trailer (sold the boat shortly after buying the vehicle), 4) I appear to have a statistical outlier.

As to why I am replacing them before they are totally shot? Good question. I am in the process of getting everything ready for my anticipated "Class of 2013" status, and trying to get any and all major expenses taken care of before I pull the plug. I'd rather put the money out now than later and, with that many miles on them, I know I'll be doing it in the not-too-distant-future. Not my normal way of doing things, but that's the thought process

 

[travelover]

On replacement brake rotors, I've run across one interesting item. The shop guy was telling me I needed to replace the rotor as it was down to the minimum thickness, which he showed me with a micrometer. Since he had the replacement rotor right there, I asked him to humor me and measure the new third party rotor as well.

It was thinner than the old rotor.

Yea, this is what I was getting at when I was pestering Dave about the actual difference between good and crummy parts.

 

[rbmrtn]

On replacement brake rotors, I've run across one interesting item. The shop guy was telling me I needed to replace the rotor as it was down to the minimum thickness, which he showed me with a micrometer. Since he had the replacement rotor right there, I asked him to humor me and measure the new third party rotor as well.

It was thinner than the old rotor.

Sounds like the shop was just trying to sell you a new rotor. The repair manual for your vehicle will have the specs and wear limits. Mine for instance 28mm normal, 26mm repair limit so it has 2mm of wear. The replacements should meet these specs even on a cheap one.

 

[Nords]

On replacement brake rotors, I've run across one interesting item. The shop guy was telling me I needed to replace the rotor as it was down to the minimum thickness, which he showed me with a micrometer. Since he had the replacement rotor right there, I asked him to humor me and measure the new third party rotor as well.
It was thinner than the old rotor.

Whoops, busted...

 

[ls99]

Most rotors have the minimum thickness cast into them, near the hub area. At least on my GMC's and Jaguar.

 

[ERD50]

What are some typical numbers for allowable thickness on the rotors? What I'm wondering is, why not just make them a bit thicker? It seems we are talking small fractions of an inch, right?

And before you say "unsprung weight", I can't help but notice that tires on cars seem to be getting larger (and therefore heavier). Seems to me that I used to buy 14" tires on the smaller-to-midsize cars I owned, then they started coming with 15", and now 16". Upgrade beyond the base model, and you start seeing 17-18-19-20" tires.

What's up with that? It seems the larger tires go up in price significantly, yet I doubt they wear that much longer. One that I looked at (same series), had a 3% delta in Rev/Mile between a 16" and 19" rim, and the larger is 17% heavier (~ 4 #). But the 16" cost just 53% of the 19". Not sure if that is typical, but I bet it's close.

-ERD50

 

[NW-Bound]

Eh, these big tires look cool! Do people need any other reason?

Same thing with fancy low profile tires on pick up trucks! How are those going to help handling on those trucks to make them as maneuverable as sports cars? Look is everything and the only thing (though I personally do not think they look all that good on a truck, but I guess it might be just me).

 

[rbmrtn]

Called plus sizing, putting larger tires on than OEM specs

+Better handling, cornering, traction etc, Looks...

- Cost a lot more for tires and wheels. performance improvement not that great,
poor ride comfort, poor winter performance

Plus sizing - Wikipedia, the free encyclopedia

 

[imoldernu]

Curiosity question for Dave....

At one time in my career... many moons ago, I was involved in a large retailer auto service think tank, with more than 200 Service Centers... (similar to the Sears Auto Service Center)s...
One of our major challenges was to increase the labor income... ie:, the profitability aside from the income from tire/battery/repair parts sales.

One of our projects was a 4 wheels off inspection of every car that ended up in our shops. It was a free 12 or 18 point inspection of the major categories... brakes, fluids, battery, tires... etc.. The inspection was followed up with a postcard reminder three weeks later. Soft sell, confidence builder.

Our Shop Managers and employees hated the program.

In the 6 months trial, our labor recovery... (labor income % to labor cost), changed from 80% to 130%. It was obviously the right thing to do, but pushback from the Managers and employees resulted in dropping the test.

This was more than 25 years ago. Now I wonder, as I see many underutilized brake and muffler and tire shops, why this free wheels off inspection is not being used.

The idea was to "show" the customer his/her problems, and use a softer sell, instead of using the fear factor.

It grates on me to see a three bay auto service with two bays empty.

Just wonderin'... Whaddya think?

 

[ls99]

PA has a good system, once a year safety inspections. + emissions test, which I loathe.

Especially in western PA, the terrain has lots of ups and downs, many steep. I feel good about the safety inspections, performed by independent shops. Clearly they have a motive to find things to fix, thus the inspections are thorough. I have the peace of mind knowing that guys who know most vehicles' weak points look at them carefully. It is a very thorough check, takes an experienced mechanic a good part of a half hour with the vehicle in the air on the lift, bright lights shining everywhere. Then a test drive.

I know many who think the emission part is important, I think it is annoying, especially since OBDII hacks up a nasty glob, and check engine light with minimal deviation from optimal function. In PA there is also the brilliant system, for emissions: even though my suburban is OBII compliant, and many diesels are compliant as well, over 7500lb GVW they require a tail pipe test. Huh?

By the way very few authorized inspection stations have the tail pipe test machinery, most just turn them off. They cost a fortune to certify, repair and maintain, yet not mandated to have even though they authorized inspection stations. Riiight, makes perfect sense.

Take Maryland, please!
They do emission checks, but no safety checks, except when transferring title to new owner. You can drive a hunk of junk, if the parking brake holds, as long as it does pass emissions, good to go.

 

[rbmrtn]

Here it take just long enough for the tech to peel the old sticker off and put a new one on. If you know the right person you don't even have to do that, they'll give one or several and you can put it on yourself. State law limits the charge to $5, which would not even cover the cost of putting the sticker on let alone do a real inspection.

 

[meierlde]

Here it take just long enough for the tech to peel the old sticker off and put a new one on. If you know the right person you don't even have to do that, they'll give one or several and you can put it on yourself. State law limits the charge to $5, which would not even cover the cost of putting the sticker on let alone do a real inspection.

In Tx the cost depends if you are in a metro area and need a smog check or not, if you do its $40, if you don't because you live in the boonies its $15. Note that Tx does give a new car a 2 year sticker because I guess they figure it will take that long for a lot to go wrong with a new car.

 

[meierlde]

Called plus sizing, putting larger tires on than OEM specs

+Better handling, cornering, traction etc, Looks...

- Cost a lot more for tires and wheels. performance improvement not that great,
poor ride comfort, poor winter performance

Plus sizing - Wikipedia, the free encyclopedia

Of course even OEM tires have increase in size my Cruze comes with 16 inch tires, and I believe pickups now come standard with 17 inch wheels (it was 15 in 1985 and 16 in 2001) I recall my 76 volarie (a real piece of junk) had 14 inch wheels. I suspect the larger wheels reduce rolling resistance a bit thereby helping fuel economy a bit, and today every little bit helps.

 

[kumquat]

And before you say "unsprung weight", I can't help but notice that tires on cars seem to be getting larger (and therefore heavier). Seems to me that I used to buy 14" tires on the smaller-to-midsize cars I owned, then they started coming with 15", and now 16". Upgrade beyond the base model, and you start seeing 17-18-19-20" tires.

What's up with that? It seems the larger tires go up in price significantly, yet I doubt they wear that much longer. One that I looked at (same series), had a 3% delta in Rev/Mile between a 16" and 19" rim, and the larger is 17% heavier (~ 4 #). But the 16" cost just 53% of the 19". Not sure if that is typical, but I bet it's close.

-ERD50

Everthing's possible. My 50 year old toy came with 13" steel wheels and a high profile tire (the only ones made). It now sports 14" alloy wheels and a lower profile tire. Roughly the same diameter and, while I haven't weighed them I'd guess, a slightly lower weight, more or less the same diameter.

I'd say that tires are getting smaller and therefore lighter, but the wheels they are on are getting bigger. Are those wheels getting heavier? Unsprung weight combines tires and wheels. What weighs more steel or rubber. I don't pretend to know but it may be a sawoff.

As an aside, I've never seen anything dumber than an 'off-road' pickup with 23" 40 profile tires. If you want to go 'back country' you want the highest propfile available. Why smash those nice alloy wheels on a 3" rock?

 

[Nords]

Called plus sizing, putting larger tires on than OEM specs
+Better handling, cornering, traction etc, Looks...
- Cost a lot more for tires and wheels. performance improvement not that great,
poor ride comfort, poor winter performance

The techniques in that article seem to attempt to keep the tires the same diameter. But I've seen plenty of cars where the tires are clearly bigger than the fender wells were designed to accommodate. If the diameter of the wheels is bigger, then the tires have fewer rotations per mile and the speedometer would register a lower speed. I guess going from 16" to 17" would reduce the speedometer reading by about 6%, or about 4 MPH at 60 MPH. Does this somehow get adjusted, or is it even considered significant?

 

[kumquat]

Well nords, are the [-]wheels[/-] tires bigger in diameter or width? My 50 year old toy has bigger wheels but smaller tires such that the tire diameter is about the same. However, the tires are a bit wider and barely fit in the wheel wells. It is a problem.

It's not hard to calibrate 50 year old speedo's (for a certain speed, ie. 60 mph). OK, it's not easy but it can be done. Usually because the speedo has 'lost it'. A 6% difference on a new car seems close to tolerances unless the speedo is GPS enabled.

 

[jazz4cash]

Curiosity question for Dave....

At one time in my career... many moons ago, I was involved in a large retailer auto service think tank, with more than 200 Service Centers... (similar to the Sears Auto Service Center)s...
One of our major challenges was to increase the labor income... ie:, the profitability aside from the income from tire/battery/repair parts sales.

One of our projects was a 4 wheels off inspection of every car that ended up in our shops. It was a free 12 or 18 point inspection of the major categories... brakes, fluids, battery, tires... etc.. The inspection was followed up with a postcard reminder three weeks later. Soft sell, confidence builder.

Our Shop Managers and employees hated the program.

In the 6 months trial, our labor recovery... (labor income % to labor cost), changed from 80% to 130%. It was obviously the right thing to do, but pushback from the Managers and employees resulted in dropping the test.

This was more than 25 years ago. Now I wonder, as I see many underutilized brake and muffler and tire shops, why this free wheels off inspection is not being used.

The idea was to "show" the customer his/her problems, and use a softer sell, instead of using the fear factor.

It grates on me to see a three bay auto service with two bays empty.

Just wonderin'... Whaddya think?

Our Chevy dealer does a 27 point inspection + tire rotation which ranges in price from "free" to 30 bucks with a lube/oil/filter change that would normally run $35 all by itself. It's basically what you describe...they measure brake pads, tire tread depth, battery condition and provide a written report. Even though I do most of my own maintanance, I find it extremely valuable since we are a family of five vehicles with 3 young drivers. If they say an air filter or whatever is required, I replace it myself but I often wonder how long it would have taken me to find the burned out license plate bulb on my daughter's car. Dealer charged 4 bucks to replace and I think that was fair.....police around here just love writing $75 tickets for such things.

 

[Finance Dave]

Sounds like the shop was just trying to sell you a new rotor. The repair manual for your vehicle will have the specs and wear limits. Mine for instance 28mm normal, 26mm repair limit so it has 2mm of wear. The replacements should meet these specs even on a cheap one.

Sometimes the min thickness is also cast into the rotor on the inside hub. Keep in mind that just because it's thinner does not mean it's lower quality. Could be different material or different ventilation in between or so on.

 

[Finance Dave]

What are some typical numbers for allowable thickness on the rotors? What I'm wondering is, why not just make them a bit thicker? It seems we are talking small fractions of an inch, right?

And before you say "unsprung weight", I can't help but notice that tires on cars seem to be getting larger (and therefore heavier). Seems to me that I used to buy 14" tires on the smaller-to-midsize cars I owned, then they started coming with 15", and now 16". Upgrade beyond the base model, and you start seeing 17-18-19-20" tires.

What's up with that? It seems the larger tires go up in price significantly, yet I doubt they wear that much longer. One that I looked at (same series), had a 3% delta in Rev/Mile between a 16" and 19" rim, and the larger is 17% heavier (~ 4 #). But the 16" cost just 53% of the 19". Not sure if that is typical, but I bet it's close.

-ERD50

larger tires improved ride quality and in some cases sell more cars (people like big wheels). As far as them wearing longer, tires definitely last longer today than in the '70s...but I can't say for sure it's due to the size...the rubber and construction (move from bias ply to radial) has been a major factor.

Maybe I should do a post on how to read tire sizes...as a 15" is not always "bigger" than a 14" lol.

 

[Texas Proud]

What are some typical numbers for allowable thickness on the rotors? What I'm wondering is, why not just make them a bit thicker? It seems we are talking small fractions of an inch, right?

And before you say "unsprung weight", I can't help but notice that tires on cars seem to be getting larger (and therefore heavier). Seems to me that I used to buy 14" tires on the smaller-to-midsize cars I owned, then they started coming with 15", and now 16". Upgrade beyond the base model, and you start seeing 17-18-19-20" tires.

What's up with that? It seems the larger tires go up in price significantly, yet I doubt they wear that much longer. One that I looked at (same series), had a 3% delta in Rev/Mile between a 16" and 19" rim, and the larger is 17% heavier (~ 4 #). But the 16" cost just 53% of the 19". Not sure if that is typical, but I bet it's close.

-ERD50

I think it has to do with heat dissipation.... if you have thicker rotors, they retain heat more and eventually can affect braking....

You might be able to correct this with cross drilling, but then you have more expensive rotors....

 

[Finance Dave]

Called plus sizing, putting larger tires on than OEM specs

+Better handling, cornering, traction etc, Looks...

- Cost a lot more for tires and wheels. performance improvement not that great,
poor ride comfort, poor winter performance

Plus sizing - Wikipedia, the free encyclopedia

Sort of

"Plus" sizing is when you go to a larger sized RIM while keeping the overall tire diameter about the same. The goal is improved looks and better handling due to less flex in the tire sidewall, which is now shorter. Right on with all your other comments.

 

[Finance Dave]

Curiosity question for Dave....

At one time in my career... many moons ago, I was involved in a large retailer auto service think tank, with more than 200 Service Centers... (similar to the Sears Auto Service Center)s...
One of our major challenges was to increase the labor income... ie:, the profitability aside from the income from tire/battery/repair parts sales.

One of our projects was a 4 wheels off inspection of every car that ended up in our shops. It was a free 12 or 18 point inspection of the major categories... brakes, fluids, battery, tires... etc.. The inspection was followed up with a postcard reminder three weeks later. Soft sell, confidence builder.

Our Shop Managers and employees hated the program.

In the 6 months trial, our labor recovery... (labor income % to labor cost), changed from 80% to 130%. It was obviously the right thing to do, but pushback from the Managers and employees resulted in dropping the test.

This was more than 25 years ago. Now I wonder, as I see many underutilized brake and muffler and tire shops, why this free wheels off inspection is not being used.

The idea was to "show" the customer his/her problems, and use a softer sell, instead of using the fear factor.

It grates on me to see a three bay auto service with two bays empty.

Just wonderin'... Whaddya think?

That's the type of shop I used to work in...I don't even mind telling the name as it was a long time ago....

Bob Sumerel Tire & Service | Cincinnati

We did such free inspections...typically ours was when we were rotating tires...we'd check a few things even without the customer asking, and then let them know if something was "amiss".

Yes there is a fixed cost associated with those bays, nice to have them filled. In our shop, one bay was for "general repairs" with a single-post hydraulic lift, one was for front-end alignments, and one was for 4-wheel alignments...which were relatively new at that time.

I would bet that if you went to Midas and asked for a free inspection, they'd do it.

 

[Finance Dave]

The techniques in that article seem to attempt to keep the tires the same diameter. But I've seen plenty of cars where the tires are clearly bigger than the fender wells were designed to accommodate. If the diameter of the wheels is bigger, then the tires have fewer rotations per mile and the speedometer would register a lower speed. I guess going from 16" to 17" would reduce the speedometer reading by about 6%, or about 4 MPH at 60 MPH. Does this somehow get adjusted, or is it even considered significant?

The bold part is not necessarily true...as you allude to in your first sentence. As far as whether it's adjusted, it depends. WIth "plus" sizing, the overall diameter stays about the same, and no adjustment is needed. If you do go to a dramatically different tire diameter, then it depends on the type of car you have. In my case:

1) I have a '69 Camaro with larger-than-stock tires...so I changed the plastic speedometer gear to "calibrate" everything back to where it should be. GM color-coded their speedo gears based on # of teeth so this was easy.

2) I have a 2007 Mustang with larger-than-stock tires...and in this car the speedo adjustment can be made with an aftermarket tuning device that allows you to set the "revs/mile" in the car's computer. I doubt whether most shops would do this for you...but then many shops also won't put "significantly" larger diameter tires on a car due to safety concerns. Obviously if you just take the wheels in, they can't say anything....but any good service guy would advise of the dangers of doing so without some forethought.

 

[Finance Dave]

I think it has to do with heat dissipation.... if you have thicker rotors, they retain heat more and eventually can affect braking....

You might be able to correct this with cross drilling, but then you have more expensive rotors....

The main reason they don't make them thicker is weight and cost. I know it doesn't seem like much, but every little bit helps.

Actually thicker rotors will typically "handle" more heat without the associated brake fade exhibited in some cars.

As to cross drilling, there is a trade off---remember that every hole you drill also reduces surface area and creates a sharp edge where heat can crack the rotor. I've seen numerous such rotors cracked, although usually this is on "road track" cars where they do significant amounts of braking and really get them hot.

 

[rbmrtn]

Sort of

"Plus" sizing is when you go to a larger sized RIM while keeping the overall tire diameter about the same. The goal is improved looks and better handling due to less flex in the tire sidewall, which is now shorter. Right on with all your other comments.

right, usually you get a tire/wheel package to keep things roughly the same, larger rim with lower aspect tire ( larger wheel size tire that is a little shorter ). The online tire stores will do all the calcs for you. Shouldn't have to recalibrate anything with upsizing.