Why aren't cars more tuned from the factory?

[Rekrul]

Pretty simple question. I mean it seems most here gain 10-15whp just from a tune. So why doesn't BMW do it? In my mind.. the only logical answer is that tuning increases the chances of something to go wrong/wear and tear on the engine. Thoughts?

[cghempel]

Seems to me that most every manufacturer leaves some "extra room" in the tuning/parameters of their engines. I believe that it is most likely to protect the drivetrain from problems that may arise when owners are using it to its full potential for extended periods of time.

You may choose any example that you like, but for arguments sake lets choose a Ford diesel (or any diesel truck). Depending on the tune, an extra 50+ horsepower can be easily had out of a turbo diesel engine by just changing the ECU parameters. However this creates problems when towing (what diesels are designed for). Once the extra power is added, transmissions, turbos, heads backing out, etc. are all more prone to fail due to the extra stress/load experienced throughout the drivetrain.

So Ford's reasoning for not exploiting that extra power is most likely to make their tucks more reliable/durable. They design the ECU parameters to allow the truck to run "hard" for extended periods of time without failing. That is not to say that by tuning the ECU you will cause the truck to fail, you just won't be able to run the truck "all out" as long as you would have with a stock truck.

In summary, even though the engine might be able to make more power (even safely) the rest of the drivetrain may not be built for the added stress.

Note: I am not saying that tunes are dangerous or harmful to the vehicle. I simply mean that with the tune, more responsibility is placed on the driver to monitor the systems/components (think engine temps, exhaust temps, trans temps, etc. on a diesel truck) so they know when to "back off" if things get out of line.

[Richbot]

Because every hp after the ones the car leaves the factory with are traded for a degradation of something else. NVH, emissions, longevity, fuel economy, cost, compliance with the law, yada yada. They do a damn good job at BMW and most other manufacturers within the constraints they have, IMO.

[chungdae]

Originally Posted by cghempel

Seems to me that most every manufacturer leaves some "extra room" in the tuning/parameters of their engines. I believe that it is most likely to protect the drivetrain from problems that may arise when owners are using it to its full potential for extended periods of time.

You may choose any example that you like, but for arguments sake lets choose a Ford diesel (or any diesel truck). Depending on the tune, an extra 50+ horsepower can be easily had out of a turbo diesel engine by just changing the ECU parameters. However this creates problems when towing (what diesels are designed for). Once the extra power is added, transmissions, turbos, heads backing out, etc. are all more prone to fail due to the extra stress/load experienced throughout the drivetrain.

So Ford's reasoning for not exploiting that extra power is most likely to make their tucks more reliable/durable. They design the ECU parameters to allow the truck to run "hard" for extended periods of time without failing. That is not to say that by tuning the ECU you will cause the truck to fail, you just won't be able to run the truck "all out" as long as you would have with a stock truck.

In summary, even though the engine might be able to make more power (even safely) the rest of the drivetrain may not be built for the added stress.

Note: I am not saying that tunes are dangerous or harmful to the vehicle. I simply mean that with the tune, more responsibility is placed on the driver to monitor the systems/components (think engine temps, exhaust temps, trans temps, etc. on a diesel truck) so they know when to "back off" if things get out of line.

+1

[Darth One]

mostly noise and emissions, i would think. plus your average buyer would prolly think that they bought a POS with all the squeaks, wooshes and creaks coming from an aggressively modded car

[flipm3]

Many cars are also designed out of factory to still be "reliable" even if it's in the hands of someone who absolutely does not take care of the car. Meaning, the car will still run reasonably well even if the air filter is clogged or oil isn't changed. Also to meet the vast array of different types of fuel and weather conditions.

Comparing the gains tuners get out of BMWs seem a lot less compared to other car manufacturers. It seems like most tunes for the M3 get about 10-15whp, but if you look at the C63 AMG, there are tons of tunes getting 40-50whp. So it seems like BMW doesn't really leave much left over on the table.

So I assume that for most of us enthusiasts who get tunes, as long as we continue to maintain our cars properly, I can't imagine us running into any problems in the long run.

[dvpouldar26]

Manufacturers do this for many reasons from emissions, reliability, to noise. For example, on the ford gt500's, a simple aftermarket intake has 40-50 whp gains, but is also much noisier than stock; on the GT-R's an aftermarket midpipe and Cobb AP can get you 530-540awhp, but there is increased drone, increased noise, drivetrain issues, etc. There have been some reports of problems with launch control at those power levels as well as the DCT slipping without upgraded fluids, clutch packs, baskets, etc. There will always be potential left on the table, but no upgrade is free from risk. Most people who buy these cars don't want to deal with all the other things that would come up from these upgrades.

[Ateam]

I gather M division weighs the cost and benefits of every additional HP and tuning of their engine. Even people that get aftermarket tunes, do you think 15hp (either left on the table from M or in aftermarket tunes) will change the performance of this car in any measure? acceleration, track times etc. I figure they realize the cost of the 15hp in terms of driveability and wear on the engine is not worth the gain of 15hp since it will really not improve anything on this car except bragging rights of "more hp"

I personally believe the only use for a tune is if you delete your cats or have a supercharger (obviously) Otherwise to be honest I am in the firm believer category that 10-15 hp are not going to do a thing.

For your own test, just look at hte M button and how many people think it provides more power, simply because throttle response is remapped and it feels like it has some more power. Tunes can accomplish a similar thing and perhaps a car will feel a bit faster but not necassarily much different in real life. Not saying all they do is adjust throttle or saying they are dishonest in anyway but changes can often feel a bit different than the numbers they actually produce.

[IMG]

Originally Posted by Richbot

Because every hp after the ones the car leaves the factory with are traded for a degradation of something else. NVH, emissions, longevity, fuel economy, cost, compliance with the law, yada yada. They do a damn good job at BMW and most other manufacturers within the constraints they have, IMO.

+1

[The Database]

You won't be gaining much from a tune on the newer M3's with just exhaust and an intake. Many other cars you could gain upwards of 30 no problem. The factory tunes these cars fairly well.

[Rekrul]

I guess what I was getting at, was that perhaps these tunes are not so great for the longevity of the motor or other parts. I was considering going catless and tuned but I'm not so sure anymore. Not to mention voiding my warranty is worrisome.

[SamS]

Some cars do get a tune from the factory, i.e. 335is, or Performance pack option for N55 3-series.

[shay2nak]

warranty, gas mileage, emissions, reliability, noise, regulations, extra cost...yada yada yada.

[Grail05]

Originally Posted by cghempel

Seems to me that most every manufacturer leaves some "extra room" in the tuning/parameters of their engines. I believe that it is most likely to protect the drivetrain from problems that may arise when owners are using it to its full potential for extended periods of time.

THIS...

[Moxie]

Originally Posted by SamS

Some cars do get a tune from the factory, i.e. 335is, or Performance pack option for N55 3-series.

Alpina - Took these a couple weeks ago @ the local dealer -