Hi guys. Need some advice. A couple of weeks ago I added the GM - Brembo big brake kit on my 2022 RST 6.2. I only drive the vehicle in weekends and have placed roughly 100 miles on it since adding the brake package. Problem is, I can clearly sense a difference with drivability. I understand the larger rotors may weigh more and possibly even the larger caliper but My G-D!! My mpg is now at 12!!! My acceleration seems labored as if I am towing something. Never have I felt this in a car. Even the acceleration sound driving normally seems as if my engine is working harder. I ultimately went back to the dealer where it was installed. They placed it on lifts and stated they see nothing wrong because the wheels / rotors are spinning freely. After driving for an additional 30 miles with mpg plunging to 11, I have made an appointment and will not accept any other excuses from them. Not sure what the tech may have done. Dragging calipers, brakes not fully releasing? Is it possible he may have tightened something too much where my ebrake is slightly holding or something. Any ideas or thoughts would be greatly appreciated. My steering feels heavy also and it just seems as if more weight has been added. Really thinking of removing these things and getting my lively RST back to stock.
Gm Brembo upgrade added...sluggish acceleration and much lower mpg.
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swathdiver
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That doesn't seem right to me either. If the current dealership can't get the job done right, you can certainly take it to another one.
When stuff like this has happened to me, I bypass the service writers and slip around back and get with the mechanics and find the right man for the job.
When stuff like this has happened to me, I bypass the service writers and slip around back and get with the mechanics and find the right man for the job.
This is a good case for using a remote-reading infrared thermometer. You can drive a bit and then measure how hot your rotors and hubs are.
The one I have came from Radio Shack and is about 15 years old. Sorry I can't recommend any particular current one. Here is one example: https://www.summitracing.com/parts/wmr-w89722
The one I have came from Radio Shack and is about 15 years old. Sorry I can't recommend any particular current one. Here is one example: https://www.summitracing.com/parts/wmr-w89722
I would have doubts about it being brake related, probably something else
have you been driving it harder since the brake upgrade?
have you been driving it harder since the brake upgrade?
Not at all. Used as the highway cruiser / highway family hauler for trips.
lot of members here have upgraded there brakes in various ways including myself and have zero effect on mpg, even if the brakes were dragging a little bit you most likely wouldn't even feel it. It's probably just coincidence especially if you can spin the wheels easily by hand.
I am not saying it's impossible you could bring your concerns to the "service manager" and ask to have it double checked with more than just spinning the wheels, at the same time tell them you have experienced a noticeable drop in mpg and ask to have it checked with a scanner.
DuraYuk
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You increased the rotational weight. I wonder how much more each rotor weighs compared to stock. Even 1 pound per corner would be huge.
I'd disconnect the battery for a bit and reset and drive and see how your mpgs do.
What was it previously ? Sometimes crappy gas cab do it too.
Don't always assume the job was done incorrectly. Pretty hard to mess up this upgrade. Could just be a coincidence.
I'd disconnect the battery for a bit and reset and drive and see how your mpgs do.
What was it previously ? Sometimes crappy gas cab do it too.
Don't always assume the job was done incorrectly. Pretty hard to mess up this upgrade. Could just be a coincidence.
This is getting a little out there. OP is not driving a Miata on the autocross track, he is cruising down the highway with his family in a 5,500 pound SUV with over 400 horsepower. The additional weight is completely irrelevant to the problems that the OP is having.
Something is not right with the vehicle, which may or may not be related to the recent work that had been done. Needs to be sorted by a knowledgeable mechanic...
Something is not right with the vehicle, which may or may not be related to the recent work that had been done. Needs to be sorted by a knowledgeable mechanic...
Holy Roller
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I agree. Increased rotational mass was the first thing that I thought of.
B.S. i added Baer erradispeed brakes to all 4 corners of mine those are way more than a lb extra each, did not change even a fraction of mpg, neither does adding 500+ lbs of people and gear. what does change it? pushing the big pedal.
The weight difference between the Brembo's and stock are negligible; the mpg didn't change due to rotational weight difference.
If you have brakes dragging enough to impact mileage you will be getting heat out of the rotor(s). Drive it for 10 miles, come to a stop without using any brake, if they are dragging that much, if you hit neutral it will stop. If they are hot you have an issue.
Changing the rotors doesn't involve setting any tension on say the wheel bearings or anything like that, so that isn't an issue.
If you have brakes dragging enough to impact mileage you will be getting heat out of the rotor(s). Drive it for 10 miles, come to a stop without using any brake, if they are dragging that much, if you hit neutral it will stop. If they are hot you have an issue.
Changing the rotors doesn't involve setting any tension on say the wheel bearings or anything like that, so that isn't an issue.
Hint: it’s not the brakes.
RST_FRED22
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Maybe try lifting up the truck and see if the wheels spin freely, maybe bad calipers? Do you smell anything while driving?
Re-read the original post.
Chad G 1979
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What is it then? All he did was have the brembos installed and his acceleration is sluggish and mpg took a nosedive. Dealer claims they are fine, but did they really check?Re-read the original post.
I don’t know what it is, I just can tell you it isn’t the brakes. And it was out on a lift and wheels spin freely like the first post stated. It’s an issue that will require an actual diagnosis which is hard to do over the internet. Rolling mass difference? Please. I’m running 16” Wilwoods on my 02 and like others have said it makes zero difference on a truck this heavy. If they were dragging enough to cause a drop in acceleration and mpg they would be getting so hot it would be obvious. So I can say with 100% confidence it isn’t the brakes. It’s something else.
that's why I asked if he was driving it differently, you know putting on performance brakes means you gotta test em out right? who spends a few grand on brakes and doesn't go out and see how they perform.....
I know I test my brakes and supercharger out constantly.
Have an appointment for Thursday morning. No extra heat coming from any of the wheels or rotors that I can detect. No weird smells neither. Mpg plummeted beyond belief! I drive like I'm driving Daisy on Sundays. 6.2 and I would easily average above 18 or 19 mpg. Since change, I am at 12! I literally just went and boosted psi up to 42, 43 in each tire to raise this horrid mpg. It helped alot but not quite sure if I really want to be rolling like that. I used to keep it 37. Is there anyway possible may e the ebrake would've been adjusted or torqued differently where the car can feel sluggish accelerating? I'm scratching my head here. I regret not weighing the rotors and brakes vs stock. I still have all of the stock parts so worst case scenario I'll go back to stock set up. One thing I can say is there is a nice big increase in rotors size from about 13 to 16 inches up front.
Just had my buddy test drive it. I feel he gave a better description of what's going on. It feels as if I am driving with my emergency brakes on. Exactly what it feels like. I literally went into my beater 2014 Accord and drove down the block with ebrakes on and that's exactly what it feels like! Steering feels more weighted, acceleration seems a bit labored and even rolling on drive on a flat road the Tahoe is barely rolling. I just. Amt wait for Thursday. Smh.
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