Ordered Renntech tune 15 s550
 

Ok, I see lots of tune questions so I figured I would post my experience up. I choose between Renntech and Weistec and went with Renntech for two reasons. One in full disclosure I have used them before and like the results. The second was warranty. Renntech is installed by a couple local dealers and i know if I have an issue they will pay as the dealer installs them also. They can't deny what they install.

Honestly Weistec is 1/2 the cost and has a lot more power. Just don't want to mess with my warranty. I know some think they will still deny but I have had before and never had am issue with being branded in any way.

In any event today the order was placed with Patrick. He is knowledgeable and courteous. The biggest thing I look for is customer service and as usual its top notch with a easy order and always a return email ASAP. I forgot to ask for next day shipping so it will be here Friday.

On Friday I will install and give my dead honest review. Im going to try and get a 0-60 app for my phone and do some honest 0-60's also.

Update late Friday or Saturday!!!!

Is it just a module that you bought? I did that on my 2007 S600 and I was very pleased. 30 minute plug and play installation and it improved my car's performance big time and my dealership never fussed at me. They still remember me doing it.

Curious when you say a Lot More Power. Also, I'm not sure if they both ship you the programmer with the ability to remove and re-install tune at your discretion. In the past, you had to do an ECU swap/
The only difference I see 10Ft-Lbs.:
Ren: 540HP / 705TQ $2,480.00, Dealer can get a 10% discount. https://www.renntechmercedes.com/ind...22-s550-detail
Wes: 540 Horsepower, 715 Ft-Lbs Torque $1,499.99 https://weistec.com/all/mercedes-ben...u-upgrade.html

Your looking at the Renntech 93 octane tune where Weistec says theirs is 91 octane.

I guess I should explain if your not from CA. In CA you cant get 93 octane gas so it limits tunes. Weistec is based out of CA and they say their tune is 91 safe. Renntech's 91 tune is 500/625 ITS ALMOST HALF!! But the safety is what I need with the low octane although I would love the exta power.

Price is $2480 vs $1499. To me the safety is worth the difference but that is an individual decision. I have had Renntech cars in the past and have been happy with their service.

This is not the ECU swap it is the programmer. Weistec is ECU swap deal.

I have to say I go through a lot of cars and selling a Renntech car adds value to the vehicle where Weistec is not as widely known as I posted on their thread if they were smart they would start badging their cars.

My service advisor once said that they perform the tune but i wonder if you do it through them if they provide you with the module to flash it back and forth?

If i were to do this i would prefer the dealership do it then theyd have an even tougher time denying warranty work whereas if you just did it youself.

Thank you for pointing that out. Not to many 93+ gas stations around. My local MB dealer will do the tune from Ren and offers a 10% discount. Ren actually will get you the name of a local authorized MB dealer. Now with the ability to add and remove the tune at will, it is even easier...

Ren now provides the tuner and you can switch back an forth with the tune. So before you go to the dealer, you can remove the tune, then put it back after. In the past and with some other companies, you must remove the ECU and ship it to them to re-apply the tune at an additional cost.

OBDII tunes are now the way to go. Eurocharged is another option with warranty.

For accurate performance results, get a Draggy. It’s cheap and as accurate or better than Vbox.

A phone app alone won’t do...

The fact is just like Dinan the reason you pay the extra cash is the warranty. Im not talking about a warranty a shop says they cover and has never paid out but the effect of these tunes on a factory warranty.

This is my wife's low mile car that I kind of just took over. It has Benz extended warranty from new and honestly if something was going to happen 4 years later it would have but its that peace of mind.


Just like I knew when I had Dinan stuff BMW would cover I know my dealer will do the same as I have had other Renntech cars with zero issue. I can care less about tuners warranty as I know how that would go. I am leaving a lot of HP/TQ o the table as I believe the higher number tunes just don't take into account the engine vs just making hp. Look at factory s63 numbers the are close and look what Benz does to those engines to handle it.

Just want a little more power to get me through the day not looking for all out car if I was that would effect my purchase. Its easy to make crazy power with turbo cars its not that easy to make it safely and without issues.

I'll report what happens!! I have no problem saying it sucks or it is awesome.

Are you making any other modifications to the car that they offer ie transmission upgrade or exhaust?

You are going with the 91+ octane tune correct?

Very interested to how it turns out!

As far as I know they don't offer tranny tune? I don't think it is needed. Actually hard shifts were a problem with the s63's to me so it has no value to me.

I have to get 91 im in CA.

I talked to Patrick about the muffler but have to see if its will wind up being mine or wife car first. Remus also offers good option but last I saw they were sold out.

Ill report this weekend.

Ok, it came a day early and of course I installed it within ten minutes throwing testing the stock 0-60 out the window. Simply turn key to 2nd position and install and two min later its done. I had to restart twice to clear warnings as per instructions and it was good to go.

I am fairly impressed for just a tune although knowing the 93 tune is that much more of course I would love to feel that also.

I think a lot of guys and gals are like me coming from US muscle cars with big displacement and you expect this boom low end hit and no it is not there with the tune.

Once you put the car in Sport it just comes alive and you feel the additional power although it is still a bit delayed off the line so no smash the pedal and light the tires.

You really feel it come alive at about 2500 and up and it pulls fairly hard. Even my daughter noticed the difference sayin "Wow"



When you put he drive selector (button above sport/'economy) in Sport it real is off and on and you have to commit to keeping the pedal mashed or you get a bit of a bucking action. It moves!!

All in all I am very pleased. I did not like the S63 as I felt it was too rough for the car but this keeps it plush till you mash that pedal and then you really feel it pull in Sport mode. I am going to say I think the 91 is more than enough especially if you worry about breakage as thats a lot of power for a non AMG drivetrain to handle. The initial soft launch Im sure saves a lot of wear.

I keep my warranty. I have a safe tune. It was expensive but I can sleep at night and I guess its in range with the cars so it is what it is. I like having the exclusive Renntech car and it truly has the power to back it up.

I will get around to those 0-60's and the programmer has a stock/tune switch so you can switch back and fourth in two minutes.

Thanks to Patrick at Renntech!!! Give them a call you wont be disappointed unless you think your getting a 10 sec ride with tune.

Congrats! The tune will likely get the car into the lower 4’s to 60 depending on tires.

You might want want to consider a pedal tuner to get rid of the lag.
It’s not turbo lag you are experiencing but the pedal mapping. Cheap non-risk fix. Very popular with BMW’s as they have some of the laziest pedal response no matter the power.

Also known as pedal box...

Ok, had this out today with the family and it is a big difference on the highway where you can open it up and most pulls are from a roll. Normally I have to keep looking as Im hitting 80 now its 100 all day and you really have to watch as it just pulls so smooth. What I like is its not as rough as the early s63's. I do not like the S63 but like the s600 and can say its more of a s600 smooth pull to it. I personally would rather just have a e63 vs the s63.

If you own one for a few years like we have and are passing on a new ride the $3k is expensive but it really changes the car making the drive special again. If I get the wife a new car Im going to also do their exhaust.

Wolfmann I had one on my BMW and yes it makes a big difference. Not sure after driving it I want it on the Benz I like the swoosh take off but it does ruin the testing of a new tune.

Once again I also cant say enough about them as a co and Patrick is a big part of that. I have had a week of bad service form some expensive purchases and the customer service was a great welcomed change!!

stay tuned!!! LOL!!!

Be careful with your tunes and make sure it's a quality tune programmed to work with your car and driving conditions. There are piggyback tunes that reside outside the ecu and only alter the data going into the ecu, thus the ecu adjusts to the manipulated incoming data but the ecu itself doesnt change. The other type is actual programming changes to the ecu that actually affect timing, air fuel ratio, etc. I have the later done on my Porsche turbo by a well known and extremely talented tuner. I had the first type for a year or so and could never get the car running right, i.e. constant check engine lights, misfires, inefficient fueling, etc. Do the research and pay for quality. Btw, the crap tune cost the same as the good tune, so price is not a good indicator.

Ok using my Sped Logic app on my Samsung S10 phone I did some 0-60 runs.

For such a big car this thing moves quickly. Problem is I am getting some tire slip and its effecting being able to stay in it. That said first run was a 4.8 and best run of the day was a 4.4. That is simply stopping and smashing the gas down. Is it accurate? I have no idea but I will tell you that the tune made a huge difference. I would think if you had the higher HP tune you would light the tires on the run and not gain much. If I could find a clean road and power braked I am confident I could get a 4.0 but I'm done beating on the car.

After running it a few times iI realized when they test cars I have never noticed if they mention what gas they use? I would think if they have 93 vs 91 it would make a noticeable difference.

Before someone asks, if there is a way to take a screen shot of the app let me know and ill post it. I know it dint happen if you don't see it!!

Thanks for the follow up.

If you want to take a screen shot of whatever is on your phones screen you can either press the power and volume down button at the same time or swipe across the screen with the side of your palm.

Just giving you the info to take screenshots. I believe your numbers.

I'm looking at the 93 Tune. I always use 93 in the car anyway. I don't track, but like the additional power when I have the urge... Call it a sleeper...

Did you dyno before and after the tune? If not, probably would have been a good idea.

Why? The difference is beyond obvious and I'm not running the car where i would need the data.

I couldn't imagine the 93 tune. Just careful what you wish for as when it's in sport mode it become a bit on off on first gear take offs. I did not buy the s63 for that very reason. It made no sense to me in that type of car. The s600 on the other hand is amazing.The 12 is just like a huge woosh of monster power. The s63 at least the 15's were very rough driving cars and it didn't make sense to me. 0-60 in the low 4's or lower is FAST!!! especially in that big of a ride. I love fast large 4dr cars but even I have my limit.

If its your only fun car and you love stoplight racing then go for it. It would be a blast but that doesn't fit our needs.

Ok, I hate when people don't update so I will.

Two days ago wife starts car and it ran like it was low on power. She went to get gas shut it off and CK engine light came on.

Brought it to dealer and told them about tune. I honestly thought that it was going to be a huge issue. Nope!!! No problem at all. Car is still under warranty and they were able to check codes and do whatever they had to and it was all covered under warranty.

So there you have it a Renntech tuned car had the ck engine light on and it was still covered under warranty. Dealer is NOT a Renntech dealer. Car is badged and I left the tool and instructions in the cup holder hiding nothing.

What was the cause of the check engine light? Related to the tune?

I don't believe so as if it was they would have obviously at that point had to deny the warranty.

It was a random misfire but they said they didn't find anything and they cleared the code to see if it occurs again. It was low on gas and we had a huge temperature swing so it might have been gas related.

Of course my wife had to tell me it doesn't feel as fast putting it in my head they cleared the tune but it feels the same to me. Its a fairly noticeable difference. I can refresh if ii have to. its easy to go back and fourth with their tool its a 2 minute pug and play. I probably should have put back to stock before I took it there but why hide it im sure they can tell anyway.

There was a guy in line with a modified C class that sounded like a race car and he left that for service also with obvious muffler and other mods.

Can you elaborate on your note: When you put he drive selector (button above sport/'economy) in Sport it real is off and on and you have to commit to keeping the pedal mashed or you get a bit of a bucking action. It moves!

Another question, did you call Rentech when you started having problems? Also, if you trade or sell the car, will they allow you to move the tune to another car?
Thanks for the feedback. The fault is critical to know what went wrong. Its actually a bit negative that an expensive tune from Rentech is causing problems. What was Rentech's response if any?

Thanks again for being honest and posting results!

I have no idea what your talking about? The tune did not create any problems. There has been endless posts asking if tunes void warranties. I had a random misfire NOT caused by the tune and MB covered the repair with no cost to me. Showing that they did not care about the tune answering the question everyone has been asking.

Why would I call Renntech if it wasnt from the tune? I have dealt with Renntech in the past and they are aces when it comes to customer service.

You tune the car specific to its vin you cannot swap to another car.

How you got RENNTECH tune has anything to do with that is beyond me i IN NO WAY EVER IMPLIED THAT. I a actually explaining that you have zero worries when you get a tune from Renntch as MB will honor your warranty.

When in Sport the tor is crazy that first gears is a smash the pedal and dont lift or it will buck the car.