ECU Tuning - Pros/Cons ?
MBWorld Fanatic!
Joined: Mar 2002
Posts: 2,934
Likes: 387
From: Kenilworth, il usa
GT63S ePerformance 4dr, '25 Bentayga Black Ed.(wife), Wrangler and 250 MLB(kids)
> Currently, they are doing a Renntech turbo upgrade on my 2019 S63, it's my daily driver and I am still covered by the warranty as long as MB does not get their hands on my car.
so... here is where that is confusing to me.
you are covered by a "mercedes" warranty, but as soon as you take it to "mercedes" to "use your warranty" in case of an issue, your warranty will be voided
aka what good is it to have your warranty in a state that, as soon as mercedes "sees" your car, you don't really have a warranty? isn't that effectively the same as having no warranty? or do you take your car to a special non-mercedes shop that can make mercedes-warranty-approved claims?
so... here is where that is confusing to me.
you are covered by a "mercedes" warranty, but as soon as you take it to "mercedes" to "use your warranty" in case of an issue, your warranty will be voided
aka what good is it to have your warranty in a state that, as soon as mercedes "sees" your car, you don't really have a warranty? isn't that effectively the same as having no warranty? or do you take your car to a special non-mercedes shop that can make mercedes-warranty-approved claims?
By "mercedes" I mean MBUSA folks, dealer will fix everything unrelated to mods themselves, will put a claim for all the usual stuff and all is good.
If MBUSA finds out about mods, they immediately put a Status 8 on your car and any warranty work gets difficult or impossible (you have to prove it is unrelated to work you have done).
In essence. I am still covered and my dealer will perform all work unless the engine or transmission blow up directly caused by the modifications.
If that happens I get stuck with the bill for that engine (or transmission) although Renntech would share the expense (that's why I would not do any mods by anyone else, Brabus is the only other company that will fully stand behind their product).
MBWorld Fanatic!
Joined: Jul 2014
Posts: 1,248
Likes: 197
2018 W213 E 63 S AMG Sedan
Sorry for not being more clear,
By "mercedes" I mean MBUSA folks, dealer will fix everything unrelated to mods themselves, will put a claim for all the usual stuff and all is good.
If MBUSA finds out about mods, they immediately put a Status 8 on your car and any warranty work gets difficult or impossible (you have to prove it is unrelated to work you have done).
In essence. I am still covered and my dealer will perform all work unless the engine or transmission blow up directly caused by the modifications.
If that happens I get stuck with the bill for that engine (or transmission) although Renntech would share the expense (that's why I would not do any mods by anyone else, Brabus is the only other company that will fully stand behind their product).
By "mercedes" I mean MBUSA folks, dealer will fix everything unrelated to mods themselves, will put a claim for all the usual stuff and all is good.
If MBUSA finds out about mods, they immediately put a Status 8 on your car and any warranty work gets difficult or impossible (you have to prove it is unrelated to work you have done).
In essence. I am still covered and my dealer will perform all work unless the engine or transmission blow up directly caused by the modifications.
If that happens I get stuck with the bill for that engine (or transmission) although Renntech would share the expense (that's why I would not do any mods by anyone else, Brabus is the only other company that will fully stand behind their product).
Junior Member
Joined: Dec 2010
Posts: 15
Likes: 2
VW Golf
If we're talking about an ECU tune exclusively:
Pro: A jump in acceleration so minor you'll probably need instrumentation to tell the difference.
Con: Increased out of spec stress on transmission, differential, engine, etc. combined with loss of the warranty covering those items possibly exposing you to thousands of out of pocket repairs, car flagged in perpetuity at dealerships, etc.
In other words, if you're just going to dip your toe into tuning, it's not worth it. You need to get into hardware upgrades if you want serious, tangible gains and at that point you're dumping so much money into the car you don't really care about the warranty or resale.
Pro: A jump in acceleration so minor you'll probably need instrumentation to tell the difference.
Con: Increased out of spec stress on transmission, differential, engine, etc. combined with loss of the warranty covering those items possibly exposing you to thousands of out of pocket repairs, car flagged in perpetuity at dealerships, etc.
In other words, if you're just going to dip your toe into tuning, it's not worth it. You need to get into hardware upgrades if you want serious, tangible gains and at that point you're dumping so much money into the car you don't really care about the warranty or resale.
MBWorld Fanatic!
Joined: Mar 2002
Posts: 2,934
Likes: 387
From: Kenilworth, il usa
GT63S ePerformance 4dr, '25 Bentayga Black Ed.(wife), Wrangler and 250 MLB(kids)
Not the current car.
Happened only once, in 2007, a newly hired service advisor mentioned Kleemann Diff to a visiting MB tech who immediately slapped the Status 8 on my car.
I was not happy, Service manager wasn't either and wanted to fire him but I advised him it could open a whole net can of worms.....
Happened only once, in 2007, a newly hired service advisor mentioned Kleemann Diff to a visiting MB tech who immediately slapped the Status 8 on my car.
I was not happy, Service manager wasn't either and wanted to fire him but I advised him it could open a whole net can of worms.....
Super Member
Joined: Sep 2011
Posts: 598
Likes: 126
E63S 4MATIC 213
Maybe you chose the wrong tuner have always had mine mapped with massive increase in power and no issues!
