airtire

Has anyone done this with their 2019 G550? 102 extra HP

My friend just installed on his 2019 G 63 and he says it's really noticable and his MPG has gone up by 1.5.

RENNtech | ECU+ Upgrade | G550 | W463 | 530 HP / 558 LB-FT

poison123

Good way to void the warranty.

vadermerc

I was told by my aftermarket shop that this was approved by Mercedes and doesn't void the warranty. COuld have been another brand that does the same thing but I believe this was it.

poison123

LOL....ya.....the aftermarket shop is full of ****.

drew138

Does anyone know if these ECU mods eliminate the top speed limiter?

airtire

I will evaluate warranty issues at the next stage, but would like feedback from a user on the G550.

Bob Z.

iTrader: (1)

It will not void the warranty for your power seat if it stops working but if you tune and your engine or another part of the drivetrain have problems, and they discover the tune, you will have problems. I have a Cobb tune on my Porsche and it will be removed if it needs to go to the dealer but they can find out it was tuned if they look for it. As per the law they would have to prove that the tune caused a specific problem but they will have a strong case to deny repairs if you tune. Odds are one will not have problems but as the old saying goes, "if you want to play you have to pay".

BCMgunner

I to am interested in the RENNtech tune. For improved fuel economy as well as performance.

The benefit of the RENNtech is you can convert it to the stock tune yourself at any time. So unlikely to be discoverable.

Was about to pull the trigger then heard about the new Hummer coming out with 1000 hp and 11,500 ft/lb of torque (read that torque figure again a few times).

Electric vehicle but still puts it all into perspective.

Electric G is also on the way.

Bob Z.

iTrader: (1)

There is a flash counter that alerts them if there was a tune or anything else that was done - it is impossible to hide a tune once it has been loaded/unloaded.

poison123

Its amazing how many don't understand that. There is no hiding screwing with the ECU anymore. Engine blows up because you've added boost from a tune....lol good luck with that warranty claim.

obbob

First, definitely want to say that a tune will void warranty. And yes, there is a flash counter. However, the flash counter, in my opinion, is at the point of "plausible deniability". Since there are several non-tune related reasons that a car's ECU could be reflashed, one could argue that there was no tune. Also, dealer's have some discretion to "look the other way" for things that aren't glaringly obvious.

Of course, everyone's experience will be different.

DABRONX

I have had several Renntech cars and all serviced at the dealer with no issue. Many dealers actually install Renntech products thats why your paying almost double. My cars have been serviced and one with an engine issue and never was there a problem with the tune or access. They were both Renntech badged and I told the adviser the tuner was in the glovebox. Look up Renntech MB dealers in your area. They will do the install at the dealership.

My 15 G550 had their tune and the difference was noticeable but not very noticeable if that makes sense. It made the truck more drivable to me.

My S550 has their entire kit and the difference is very noticeable. It's a close to 0-60 in 4 sec car which is crazy on 91 octane.

One thing to keep in mind is where you live and available gas. If your in CA like me even your stock G63 will never have the HP or 0-60 times posted as thats with 93 octane. Renntech actually sells different tunes for 91 octane which unfortunately has about 1/2 the HP difference.

Bob Z.

iTrader: (1)

I just looked at the dealers that support Renntech and one happens to be the place that I placed my order with so I emailed the POC there and am waiting to hear back from him and what he says in regards to the tune, warranty, etc.

johnnyderm

Do the Horsepower figures on the dashboard (in AMG mode) change to the new HP numbers? Would the computer system pick it up and show on screen? Curious.

CClement

The numbers on the display do not change with a tune. That being said, those numbers are really just for show, they arent accurate at all and given they don't change with a tune is proof they aren't real readings.

CClement

Did you ever get an answer on this Bob?

fabbrisd1

Well, let me "update" this thread and answer CC's question..

1. This needs to be made a bit clearer on the "how" - for the new G the ECU is reprogrammed/flashed using Renntech's "HHT" HandHeld Tuner. This allows the owner to reprogram/flash the ECU thru the OBD port in the cabin - and it is a straight forward EZ process - about 2 minutes. The HHT also allows the Owner to reprogram back to factory spec - again a straight forward 2 min process

2. Renntech has been at this a long/long time - especially with tunes for Mercedes - and is the tunes I have seen, and driven - RennTec tuning has never set off a Check Engine Light (CEL), or caused any Emissions issues, and has never led to a mechanical failure either - that is my personal experience.

3. In the US there are Federal laws that protect the consumer - in essence by doing a tune "technically" a auto manufacturer would not honor warranty if you "fried your ECU" - but I have never seen or heard a RennTech tune causing any other type of mechanical or system failure that would have ever brought up "not honoring warranty" on any other system or component - and frankly US warranty law would protect a US owner in that case anyway.

4. The HHT allows you to program back to factory default BEFORE checking into service - if your relationship with your Mercedes dealer close/personal

5. The only "pushback" about RennTech is there a wide range of other Tuning Shops that seemingly offer the same result (so they claim) at a lower price. I have customers who have gone sown that road - and frankly there have been a good # that have resulted in CEL issues, performance issues, etc... and again there have been NONE of those issues ever with a RennTech tune

CClement

Thanks Fabb, that's pretty much what I've always heard. I've always tuned my vehicles and regardless of tune brand, my dealership has always been great, I've always been completely honest with them and usually even badge my car with the brand of tune. Again, I've never had anything more serious than a boost pressure sensor error though. I feel like a vehicle with a price tag of a G deserves the premium paid for a well recognized tuner in the MB world like Renntech. Thanks again.

Bob Z.

iTrader: (1)

Come to think of it I never did! I'll have to follow up at some point since I usually tune all my vehicles if one is available....I have a Cobb on my Porsche now.

Bob Z.

iTrader: (1)

It has been a while so has anyone experimented with a Renntech tune for their 2019+ G?

Festertester

Thought you were going to check and circle back?

airtire

I did order it and installed it. I don't notice a major difference unless I floor it, then it seems to kick in.

Make sure if you get it, that you specify you want the auto start / stop button off. I thought it came with that bypassed automatically, as that was part of the reason I ordered, but it doesn't and had to send it back for reprogramming.

Bob Z.

iTrader: (1)

I did actually but I was not told anything worthy of posting, which was surprising since they have a great rep.

airtire: notice any gas mileage change?

The Butcher

This is annecdotal, but a friend from the gym talked to an MB dealer local to us who is on the Renntech site, and he said he didn't care if it was Renntech tuned (in terms of warranty coverage). I haven't talked with him myself, but I plan to add the Renntech G63 tune soon (after talking with the MB dealer myself to confirm warranty coverage). My wife's G65 has the Renntech tune on it, and it's a monster.

ima55r2

Your friend is right in that dealers really don’t care what you do on the vehicle because they don’t pay for your warranty claims. A questionable or big ticket repair is going to get MBUSA involved and they decide if it is covered. The service techs don’t get paid to fix or look for anything not on the service order or a bulletin so checking for the flash count is not on the list unless something unusual breaks.