bob2011

Ok guys, so me and a buddy of mine have been having a friendly discussion about tuning and what not. Basically he's saying that tuning a car doesn't do anything to reliability, because the Manufacturer tune is conservative and caters to all parts of the world for different fuel qualities and stuff. I'm saying however that any tune that is not to OEM spec will hurt and decrease the longevity of an engine do to it running at a higher HP and TQ rating. Plus, wouldn't the OEM manufacturer that has millions upon millions of dollars for R&D already have squeezed every ounce of reliable power out? Sure you get more power out of a tune, but I'm sure you are sacrificing Something for that extra amount of HP. What is your guys opinion on the matter?

P.s no disrespect to any of the tuners on here! Keep doing what you guys are Doing!

thefisch

I am in no way qualified to answer this question as I have never tuned a vehicle nor do I have a background in engineering, but I am interested in the answer. I haven't googled it but I bet the answer is out there and likely debated in tuner-oriented forums.

I would assume (bad idea I know) that the folks who tune tend to drive more aggressively than your average driver and that habit may lead to premature wear. But how do you go about attributing that to either the tune or aggressive driving? My sense is that manufacturers build their cars so that under normal driving conditions you are no where near the limits of the design and parts. So if you tune a car and drive normally with slightly faster acceleration and perhaps better fuel economy you are putting slightly more stress on the car but are likely well within its limits. If you do experience a breakdown or repair on part of the powertrain affected by a tune, chances are it was going to happen anyway.

It's another story when you start pushing the car and driving harder, and if you don't do that then I wonder why you'd bother investing in a tune or other modifications unless there are efficiency gains.

cc16177

Well my dad always told me that tuning a car reduces the lifetime of the engine and "there's no question about it" but when 4th/5th gear on my Mazda gave out he also told me "just use third" and minutes later my entire transmission blew up on the highway.

So, yeah. I'm curious about this as well.

PaulE550

I responded to this with a detailed answer, but the session timed out. Not going to bother re-typing everything again. So I'll simply see if someone else responds. :-)

CarolinaBluetec

Would you buy a used car that had been "tuned"??? Think about it and you will have your answer.

PaulE550

It would depend on how aggressive the tune was, but I would have to say generally NO.

thefisch

I got real kick out of this. Partly because it's happened to me before. You've typed out all your thoughts and then it's gone and you're like oh well that's not worth doing again. Also, because it reminded me of one of the best Seinfeld episodes ever, The Strike. Love that part when Kruger gets locked out of his office and decides to just go home. The Human Fund, Festivus, etc. It's a classic.

Quadcammer

This is a general question (or statement) that cannot be generalized. Every car or drivetrain combo is at a different percentage of max reliable power. Similarly, every tune is different in how much it stresses components. There are tuners looking for glory who will make as much power as possible, and too bad if a few motors blow, while others look for reliability first.

The bottom line is that any time you add power through tuning, you increase the chances of failures. It could mean going from 2% to 3% or 80% to 95%, but it all depends on the platform and the tune.

Johnny Rad

I liked the bit about getting advice from "Dad" ... I get good, bad and ugly advice from my pop. At least in my case, I get what I pay for and I'm not paying anything for his advice (ha). He's a great guy and I love him to death, but he can be full of $h1t.

bob2011

I see what you are saying, and I think I have to agree. If something was gonna fail on a powertrain component, it was gonna fail regardless of tune or not. The tune just helped it fail faster.

PaulE550

Yes, loved that episode too. Classic.

On my original comments that vanished into space, I wrote out four paragraphs and I guess I just don't type fast enough to beat out the session timer on the site. Next time I'll write out my comments in Word or Notepad and then cut and paste them into a post.

bob2011

bob2011

haha I hate when that happens! I'm hoping for some technical answers as well!

bob2011

That's funny you say that, I was watching a video about a Tuned E63 that was pushing like 700 horses and the guy was doing burnouts and launching it everywhere. Coincidently I went to cars.com to find a used E63 and that same E63 from the video was on sale! I went back and commented on the dudes video and he confirmed it was the same one, and he had the audacity to say it was Very clean and VERY well taken care of! LOL! But you are right, generally I would stay away from a tuned car, however not because of a tune, but because of the driving style associated with tuning.

bob2011

Fair enough, it's like the guys who are tuning a NA engine Vs a turboed engine. The turbo engine will probably have a higher failure rate because of the stupid amounts of power they are squeezing out, vs the NA engine tune.

PaulE550

I decided to re-type most of my original post in Word, so this should hopefully work this time. I’m looking at a tune from strictly the technical perspective based on comparative analysis of available public data, since that is my background.

The way I look at what constitutes a “safe tune” is you have to look at how MB sets up (tunes or more accurately programs the ECU ) the same engine / transmission pairing across their various models to determine what would be the “safe” upper limit, from the perspective of both longevity and reliability. For example, in my case I have a 2015 E550, which is the same M278 engine and 7 speed transmission used by MB in the CLS550, SL550 and S550 for 2015 as well. Yet when you look at the rated values for both hp and tq of each of these models, they are all different. They range from a low of 402 hp / 443 tq in the E550 to a high of 449 hp / 516 tq in the S550.

Given I haven’t been able to identify any major differences in the engine / transmission builds between these models, the only difference would likely be how the ECU is programmed from the factory for each of these models. Since MB, like every other major luxury auto manufacturer, does engineering stress tests of their motors and transmissions pairings to determine a safe upper limit under normal operating conditions for the anticipated longevity of the vehicle, I can see no reason why the ECU in my E550 could not be re-flashed (more correctly re-programmed) to that of a S550 with NO adverse effects in terms of either longevity or reliability. After all, the S550, with the exact same engine / transmission pairing, comes set from the factory at these levels and I seriously doubt anyone would make the argument that MB would intentionally “tune” their S class to levels that would lead to either reduced longevity or operational reliability.

Now we get to the real issue everyone on this thread really cares about. That being what is the real upper limit for both reliability and longevity, measured in years of expected operation, of this engine / transmission pairing. That is something we would need to get from someone at MB, who has access to the database of engineering data for the various engine / transmission pairings. All we need to know is the upper hp and torque limits they found for safe operational limits. This is where every discussion I’ve seen about tuning on this MB web site and others has hit a dead end. Obviously there are lots of discussions about tuning of the various models, but I haven’t found anyone from MB commenting with this type of data. So how do we realistically know if tuning the ECU of a M278 engine to say 500, 530 or more hp is still within the safe operational window for both longevity and reliability? We don’t.

Sure we can look at what the various tuner companies are saying, and I think most are genuinely trying to provide a much needed service, but that’s not the same as getting the information from the people who designed and built these engines and transmissions. That’s my two cents on the subject.

ljn21

Gold Jerry, Gold .

Johnny Rad

Nailed it.

hyperion667

most guys that tune cars don't seem to keep them long anyway.....passing the problem off to the next owner.......if there are any