ECU Tuning - Pros/Cons ?
 

I am pretty satisfied with the amount of power car has as it is but at some point may consider a ECU tune. Wondering what are the Pros/Cons tuning the car and if there are any Tuners that are approved by Mercedes or Mercedes is OK with those tunes on the car? I understand that the biggest Con would be giving up engine warranty from what I understand. But a few weeks ago I blew engine on my Porsche which had Cobb tune on it. I told dealer that car was flashed with Cobb. They ended up approving my claim and began the engine repair/replacement. Not sure if Mercedes dealers are as cool or it would be a battle ?

Also which vendors have reliable and proven ECU tunes that actually make more power ?

Oh and this is my First Mercedes AMG car :)

https://cimg0.ibsrv.net/gimg/www.mbw...db83a187eb.jpg

you have to ask your dealer if they offer any tunes with given warranty.
there are no tuners that "approved" by mercedes if your engine will be shipped for inspection to Germany in case if it blows, any electronic /mechanical change to main units will void warranty.

Dealers will always say NO to any kind of modification you do to the car. They can't tell you it's ok because it's not a MB part and they don't want to be liable.

However before I bough my car I test drove 2018 E63 Wagon that was sold by Mercedes San Francisco as a CPO car and it had Renntech tune on it. Dealer said that it was OK to have Renntech. I was quite surprised to hear that they CPOed the car with Renntech tune on it.

That's why I am asking if anyone had any experience with any particular Tuners and how the dealers are feeling about it.

you asking questions and answering them yourself.

that renntech tune was installed by dealer, thats why they were ok with that. read my post.
if you afraid to damage car, better don't tune it. any tune is a risk. there is no safe and approved.

My dealer told me that if they see a Renntech, they are flagging the car (which Mercedes gives the dealer an incentive to do, and can/will fire service advisors + technicians + managers if they do not report it)

On top of that, I've also heard it's 100% automated. aka, when your car is on the bay for service, when they plug in to your OBD-II port to check for "software" updates, your VIN is automatically flagged.

and even if you flash it back to stock, it should still know something was done, right?

yeah

it stores “change codes” across multiple different modules

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.

Just had mine serviced with software update plus a couple of recalls, came back stock as factory as update wiped of tune, clean bill of health from Mercedes! very dull stock had map put back on Friday free of charge now back to 750bhp 1000nm torque very very different animal its surprising how you get used to the cars power when mapped! you dont need special gadgets to feel the difference with a good mapping its night and day from stock its all about that torque increase sucking you into the seat! i had all my AMG's mapped and ive had a few never had an issue and always serviced at main dealer! go on treat yourself:y

large chance they didn’t tell you they flagged your VIN status R

Can you explain how one dealer would "flag" the car when other willing to CPO it and sell it to you with Renntech tune being one of the selling points ?

I am confused.

1. you tune your car (flash)
2. you bring it in for service
3. the technician plugs in OBD port to their diagnostics bench in their bay
4. your tune is detected
5. your VIN is flagged status R in the “mercedes north america database”
6. any warranty claim you submit will no longer be auto approved, but instead will require “area operations manager” review to prove it wasn’t tune related. it is up to their discretion. if they believe your fault was related to your tune, your claim is denied and you must pay (aka no warranty)

As stated never had an issue in 10 years I guess we will find out if anything breaks or fails in next 2 years🤠

I do want to go on record that I have 0 hard proof of anything I am talking about and if anything, you going 10 years tuning without getting your warranty voided just shows that everything I've gathered/pieced together/read on the internet about tuning = auto flagging is full of ****. So, mad respect and thanks for posting! I just wanted to call it out for anybody else reading that... there's conflicting evidence all over the place on whether tuning == your warranty auto-voided or voided at all. Your milage may vary and I'll STFU about it. :)

Yes agreed mate i can only go on my experience if Mercedes could find away of getting out of paying they certainly would so wouldn't want anybody to take my 10 years as concrete, maybe ive been really lucky! ( ive probably jinxed myself now :wall: ) Brabus will keep your warranty in place but your pay big bucks there 700 is over 5k for module and there 800 will cost well over 20k GBP! there 700 is quoted 0/60 3.2 and the 800 is 0/60 3.1 the 800 puts out 1000nm of torque! ive got around 750 and 1000nm in mine for a decent cost! Never STFU because thats why were on here giving our info and its all appreciated :y

that is one thing i’ve noticed

i’m glad i tuned my car because it is overall snappier

but i’m pretty sure i threw out my warranty for just 0.2-0.4s 60-130mph... not the smartest decision bang for buck wise in my opinion. i wish i had better results to share and maybe i am making a mistake

So does this apply to the lowering module also? does flash up message when plugged in but then goes when turned ignition off and re start??

i can’t say for sure with any degree of confidence but *yes* it is possible that the ECU (or any of the modules involved) could store logs/records of when the “readjust airmatic levels” procedure is ran

however, i’ve heard/read nothing as such on these forums

👍

Is the "new" OBDII ECU tuning module of Renntech also flagged and therefore detectable by the dealer/MB? Also when you set it back to STOCK before you go to the dealer?

im guessing yes if info correct! My tuner has an inside technician in Audi they sent a mapped car in and they couldn’t see anything when plugged in there tool into OBD!!

Nice FIRST MB OP, looks like you did it right with CCB and magno paint :y

Everyone has different experience and different stories and they are all true.
I have modded ALL my cars since my first modifiable car, a 200 Quattro 20V back in 1991 (a simple ECU raised the power from 210HP to 300) and had a problem with MB only once, in 2007 with my SL65 that received Status 8 by a visiting MB Tech at my dealer.
All mods were always done at my dealer, Renntech exclusively for the past 12 years, never had any problems anymore, all warranty work performed with no issues.
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.
It's always a risk and I know it and I acknowledge it, my dealer knows that I have accepted it and not going to give them any trouble in case **** hits the fan so they do the work for me.
It's always about having a history and a relationship with them, they don't do the mods for anyone else anymore because of potential risks (some people are *******s, they had a guy once who made them put Kleemann headers in his G55, they cracked after a few thousand miles and the idiot sued the dealer).
As long as everything goes well, I am covered for all components, if I blow up the engine I will take the responsibility for it, not the dealer, Renntech would most likely participate in rebuild expense but I accept the fact that I am the one taking the full risk.

> 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?

🤔