I've noticed on more and more GM (and other brands) vehicles that there has been a switch away from stainless steel for all or parts of the exhaust systems.
I haven;t looked closely at our 2019 Acadia, but the rear "bread box" mufflers appear to be aluminized steel.
I see these exhausts lasting maybe 8 to 10 years before possibly needing replacement. What often rusts out first, though, is the "flex" pipe which connects the rest of the exhaust system to the exhaust manifold. That can happen in as little as 5 or 6 years depending on type of driving and environment.
I never noticed a trend to stainless, but haven't really been watching. I thought mostly only sports cars got SS
The flex portion, is that mostly for ease of assembly? Or to minimize vibrations? No surprise at all they'd go first!
Car manufacturers have been using stainless steel in exhaust systems for years. There's quite a discussion about it in earlier posts on the forum. Here's one: Acadia Exhaust. It would be interesting to know if they switched to one of these products: ALUMINIZED 409 AND 439 STAINLESS STEEL
At the time, Chevrolet did pretty much everything they could to reduce weight on the Z06. Thinner windshield, ti exhaust, coupe roofline only... got it to a hair over 3100#, later models gained weight.
I have worked at a company producing OEM exhaust parts for 20 years and every part we have made is stainless steel.
Speleos is right. Typical exhaust parts from the catalytic converters back are 409 grade stainless steel. It is the least exspensive. Some have aluminized coating and some without. The coating is often one of the first items to be removed after a couple years of production to save cost.
Some newer programs are using 439 stainless steel which has better high temperature corrosion resistance.
409 stainless will show signs of red rust on the surface after a relative short time of use, so many people confuse it with plain carbon steel
I have no problems or see a reason to replace the exhaust on my 2007 Acadia after 12 years of use and Michigan winters with copious salt on the roads.
when my 2012 Acadia gets up to temp it starts to show traction control off then on. sometimes it will show service battery, my dash lights and head lights will deem or go out for a second, and after a few minutes the transmission will not shift properly or at all.
I have 2018 SLT1 FWD Acadia that now has appx 5800 miles on it. I’ve noticed two things while driving that are a bit concerning, but would like to see if others have noticed the same symptoms with theirs.
1.) When the transmission shifts from 2-3 it has a more noticeable shift than any...
Recently I have noticed that when driving my 2017 Acadia at slow speeds when shifting from 2-3 (need to double check if its from 1-2 or 2-3) it seems it holds RPM for a bit too long before shifting to the next gear.
This is probably more pronounced during slow speeds as vehicle is going smoothly...
when I jack up the front left and put the trans in neutral and then rotate the wheel by hand, something seems to be sliding around inside the transaxle. I can turn the wheel maybe a quarter or less with no noise but then when i turn it a little farther something seems to slide to the bottom...