L8BRAKR said:
Remember it's not hard to tune for max horsepower. Where it gets tough is spreading that power over the rev range and keeping good throttle response. Along with those, the factory engineers need to keep fuel economy a concern which may not matter to us but it does to the government.
You also forgot to mention those pesky emission standards. Lotus has to tune the car to meet the standards for at least 100,000 miles with out any major repairs. After-market tuners don't have to bother with such things. So, yea, someone can make the engine have more power (or better economy, etc.), but it is a difficult task to meet the various emission, economy, reliability, NVH, cold start, hot running, etc. requirements along with making the most power - that's where Lotus and other manufacturers spend their efforts.
I've said it many times before, everything is a compromise. For every improvement in one area, something else is suffering (if only that it costs more). Finding the right balance is what Lotus did a very good job at.