Rear rotor mileage?

[Movado750]

My 2012 X5 4.8 Msport has 71K on it. dealership said it needs rear rotors nd pads. Pads I can see but REAR rotors at 71K. I've had a ton of cars and have never had to put REAR rotors on a car with this low of miles. I bought pads and will inspect the rotors tomorrow.

Do you think this is a normal BMW thing. or is it just a suggested MFR thing that BMW says.

this is my first BMW, and have not been impressed with all of the maintenenace that BMW says it needs. I know it is all preventative issues that the dealership is required to tell us needs to be done.

Your thoughts?

[mitch808]

Usually I can go two front changes get before touching the rears. And that's with not just an x5...

Mileage had nothing to do with it though and for a rear disc, getting over 50k is great.

[RichardR0404]

My car has 60k km brake pads still have close to 10mm thickness. The reason why it is like this is because 100% of that 60k km is highway miles.

[jgrote]

Many car manufactures are dialing in the braking systems so the front and rear wear about evenly now. A lot of it has to with stability control (or other traction aids). Newer Subarus are getting 50-60k out of a set of brakes, and usually needs all 4 wheels done at the same time. My Chevy Sonic was the same way.

Now for your question about rotors. Welcome to CAFE fuel mileage goals. Rotating mass is hell on fuel efficiency, so OEM's are making rotors so close to replacement spec that there is nothing left to turn if they need to be trued up. I just did the brakes on a family member's 2014 Forester, and we just pad-slapped it (45k miles, 15% pad left). The rotors looked decent, and the pedal wasn't pulsating. I always rough them up a little with emery cloth just so the new pads will bed in better, but that's about all you can do now. I'm not sure how much BMW rotors are, but I know most cars have come down in price over the past few years.

[RichardR0404]

Originally Posted by jgrote

Many car manufactures are dialing in the braking systems so the front and rear wear about evenly now. A lot of it has to with stability control (or other traction aids). Newer Subarus are getting 50-60k out of a set of brakes, and usually needs all 4 wheels done at the same time. My Chevy Sonic was the same way.

Now for your question about rotors. Welcome to CAFE fuel mileage goals. Rotating mass is hell on fuel efficiency, so OEM's are making rotors so close to replacement spec that there is nothing left to turn if they need to be trued up. I just did the brakes on a family member's 2014 Forester, and we just pad-slapped it (45k miles, 15% pad left). The rotors looked decent, and the pedal wasn't pulsating. I always rough them up a little with emery cloth just so the new pads will bed in better, but that's about all you can do now. I'm not sure how much BMW rotors are, but I know most cars have come down in price over the past few years.

I am running NAPA rotor with ceramic pads, this combo always last very long. Just personal reference.

[pshovest]

Measure the rotor thickness. Per BMW, if rotors are above minimum thickness, they are good for (1) more set of pads.

[jgrote]

I'm not a huge fan of ceramic pads, personally, but others may (and it's fine to) have a different opinion. I personally like a more linear pedal feel than better initial bite. I generally run Hawk HPS or Stoptech pads. They don't last very long, but they do very well with heat and tend not to tear up rotors. Ceramic pads can be so hard that they wear out rotors quite quickly. Once again, this is MY opinion on how I like MY car to stop. When doing my sister-in-laws car, it gets mid-grade auto parts store stuff. It works for her. (And there's nothing wrong with those pads.)

So, Movado750 , I guess the questions I would ask you before you go out and buy anything are these:

1) How do your brakes feel right now?
2) What kind of driving do you mostly do?
3) How hilly is your area?
4) How concerned are you with brake dust?
5) How would you like the brakes to feel?

There are so many options out there now that you really can choose what it is that is most important to you.

[Movado750]

Originally Posted by jgrote

I'm not a huge fan of ceramic pads, personally, but others may (and it's fine to) have a different opinion. I personally like a more linear pedal feel than better initial bite. I generally run Hawk HPS or Stoptech pads. They don't last very long, but they do very well with heat and tend not to tear up rotors. Ceramic pads can be so hard that they wear out rotors quite quickly. Once again, this is MY opinion on how I like MY car to stop. When doing my sister-in-laws car, it gets mid-grade auto parts store stuff. It works for her. (And there's nothing wrong with those pads.)

So, Movado750 , I guess the questions I would ask you before you go out and buy anything are these:

1) How do your brakes feel right now?
2) What kind of driving do you mostly do?
3) How hilly is your area?
4) How concerned are you with brake dust?
5) How would you like the brakes to feel?

There are so many options out there now that you really can choose what it is that is most important to you.

Wifes truck and she drives about 5 miles to work each day, very flat. when I drive the car I beat the piss out of it cause that is what it was made for. I have the full Dinan exauast tune, ect. I can keep up many cars and fast trucks. The thing is a beast and goes. People are shocked at how fast it is.

I'll just do pads tomorrow morning and see how the rotors look.

I'll update when completed.

[jgrote]

Sounds like decent parts store pads will work just fine for you then. Happy wrenching!

[Movado750]

Originally Posted by pshovest

Measure the rotor thickness. Per BMW, if rotors are above minimum thickness, they are good for (1) more set of pads.

Well thanks but it does not give me a measurement of thickenss or am I missing something?

[pshovest]

Min thk is stamped on the rotor. I believe your rotors are 345 x 24

https://www.newtis.info/tisv2/a/en/e...nance/2T0SkKlE

[jgrote]

Originally Posted by pshovest

Min thk is stamped on the rotor. I believe your rotors are 345 x 24

https://www.newtis.info/tisv2/a/en/e...nance/2T0SkKlE

And requires you to have a micrometer that looks a little like this:

[pshovest]

...or this....
https://www.harborfreight.com/6-in-c...per-63137.html

[jgrote]

Originally Posted by pshovest

...or this....
https://www.harborfreight.com/6-in-c...per-63137.html

Unfortunately those won't work because you need to measure the thinnest point, and there is usually a lip at the edge of the rotor. The ones I used to use at work actually came to a point at both contact points so I could measure down into a groove if there was one. I couldn't find a pic of one like that though. The OP seems smart enough not to run with rotors that have deep grooves in them though.

[pshovest]

They will work......measure with (2) pcs of 1/4" keystock, one one each side of rotor, and subtract 0.5" from the measurement.

[yco]

high speed hard braking affects pretty much the rear.. 71K miles is not a low milage for changing the rotors sounds normal to me..

[heatmizr]

Mine called for rear pads AND rotors at 42k-ish. I doubted the rotors were done, so I just threw pads on it and figured I will check the rotors later.