ECU Tuning - Pros/Cons ?
Also which vendors have reliable and proven ECU tunes that actually make more power ?
Oh and this is my First Mercedes AMG car
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.
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.
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.
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.
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.
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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.
Last edited by Carac; Oct 9, 2019 at 02:56 PM.
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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)

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




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.
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?




