My dealer does the renntech upgrades and gave me a brochure when I bought my new CLS63 that states the ECU renntech reflash is good for 33 hp and 30 ft. lb of torque. Has anyone on here done this to their CLS63 and did you notice a difference in performance and what does this do to dependablity? Said it costs a couple of grand?

 

Yeah. You don't gain too much hp from just the ECU re-flash. However, it gives you a little better performance as you stated with the increase and it, from what I believe, removes the top speed limiter. The great part about Renntech is that Mercedes accepts it and it does not void any warranty.

 

I have the 030 package so no speed limiter. To me it is all about bang for the buck. Does it improve throttle response? 0-60 time, torque feel? fun factor? How much does it cost?

 

I would probably do a bigger Renntech package then. I'm sure you will feel a small increase in power and throttle response but nothing major. It is costly but in the long run, it is a better choice since it is does not void any warranty from Mercedes.

 

I would do it for a few hundred not a few thousand. I did a search and did not see any threads talking about the Renntech reflash. You would think if it was that good everyone would be talking it up???