Why don't cars come "tuned"?

[russellfray]

I was just wondering, if tuning a car gives more power and also usually can increases (or doesn't change) mpg, then why don't cars just come tuned for the better performance out of the factory? What I mean is - what are the negatives for getting it tuned that stop the manufacturers doing it instead of having to get an aftermarket chip or tune?

I expect cars are always tuned to still be "within manufacturer limits" on parts like turbos, so if the manufacturers pre-tuned their cars for the better performance and mpg it would boost their sales to no end.

So... why DON'T they? What are the manufacturers trying to protect/hide?

[Mollox]

I think in the first instance its 'insurance' against premature part wear etc. The safety margin allows them an extra buffer of protection in their warranty projections I am sure.

Its also likely that component manufacturs place conditions on the use of their components as part of their warranty to the manufacturer and so they could be unable to push parts beyond what the component suppliers are comfortable with from a warranty viewpoint.

Looking at the consequences of a power hike, especially in torque-rich turbo engines its clear that there would be knock-on costs associated with an increased output. The vehicle might require a stronger gearbox (cost) as the existing one may be near its safe torque limit (warranty, again), perhaps the brakes were deemed aqequate with x bhp but not with y bhp. Can the suspension cope with the increased speeds the car is travelling at? What about tyres? Will the exhaust require modifications? Do they need to fit a higher-rated speedo? (lol) etc Perhaps the car becomes dynamically unstable or insecure with the extra pace. Aerodynamic instability (early TTs, anyone) costs millions to remedy for example.

I imagine its also in many ways related to their sales strategy and their competitors. Maintaining power 'slack' in the powertrain would mean that an 'evolution' or revised model could boast an 'improved' more powerful engine at little or no cost. The new Mini Cooper S 'boasts' an additional 7 bhp and 7 lb/ft of torque. I'll eat Ari's hat if it hasn't been electronically achieved. Manufacturers could also be keeping something in the bag for any potential future 'special' version which would boast substantially more power and for which they could charge 10-15% more. A little bit of marketing bumf to paper over the dubiously revised spec and they have a limited edition cash cow to flog to us.

It could also mean that they do not want to rock the boat and enter into a "power war" with competitors - witness Mercedes and their 737 lb/ft SL65. Although quite who they are in a war with with those numbers is anyone's guess (Boeing perhaps?).

I also wonder whether much of it is emissions-based. To be honest I don't really know how much attention tuners pay to emissions regulations (perhaps they do) but with manufacturers being perennially squeezed by neverending "forthcoming new emissions regulations" perhaps this prevents outputs from soaring upwards? Ironically, tuners strive to achieve the 'perfect burn' (stoichometric combustion) and so the car should run cleaner than before.

And although in day to day driving a tuned (chipped) turbo car probably returns similar if not slightly better (thanks to a better combustion) fuel consumption, if you actually belt it and use the extra power then its inevitable that fuel consumption will be worse than before. I'm not sure if there are any similar schemes in Europe, but in the States, manufacturers are taxed according ot the average consumption of their model lineup and this might be a consideration.

Looking back on what I've written, I think the ultimate reason is preserving cost and the fact that increased output has consequential effect on other key components of the vehicle and could likely result in a swelling in manufacture cost to maintain the original car's abilities and reliability.

[russellfray]

Nice answer I will read the rest of it when I've sobered up tomorrow !

[essexr32]

Sorry Inigo, hav'nt had time to read your respose either.

But my 2p's worth. MONEY

[scooby_simon]

Inigo is prolly correct with all of the above.

A tweaked engine will expose weaknesses in other components that need to then be uprated too.

There is also the 'design limits' - we all know you can get plenty of extra oomph from stock engines. Using Scoobies as an example, stock at the start was around 200bhp, some simple mods upped that to 215 no problem.

Next evolution (P1 / STI) goes to the happy side of 260 and 300 is not that difficult at all after a trip to PPP - and really going for it can get you to around 400 if you really wanted to.

But I bet a 400bhp engine (or even 300) needs a whole lot more servicing and re-tuning to keep it sweet so there are some extra costs of ownership which evereyone will not want.

[cheechy]

Another point to consider - especially on VAG group cars is the shared parts bin philosophy.

For instance the 2.0 TDI engine has been tuned to deliver a specific co2 emissions target and fit into a wide range of cars. Therefore if this engine has to fit a number of cars then it would be prudent to suggest that the tolerances have to be within any of these cars running capabilities no?

Just another point to consider!

[Brabus]

The CSL comes tuned straight out of the box!

[scooby_simon]

Good point re emmissions.

Scooby passed his MOT on emmissions (after second emmissions test).

[BURTON]

Also alot of Car makers can't always tune the cars. I know the new breed of VW Engines that will be coming out are going to be even harder to tune!

There are alot of Approved tuners now that most of the time the Car makers don't need to tune the car cos this can show weakness' and the last thing they want is the car they have just sold to be coming back.. Hence where Alpina and RUF do there stuff.. (Just those 2 as a example)