integraleo wrote:Point is its not a new idea,all old design engines are less fuel efficient than the modern equivalent not only due to new technology but new emission laws. The fact is small turbo engined cars have been around a long long time,it's not a new clever idea. It's an old idea with new technology that's all.
I agree, the idea of small engines and turbos has been around ages no ones discounting this.
But not with the efficiency and reliability which current manufacturer strive to achieve.
The Twinair claimed to be small engined wonderland answer, the realisation is you have to rev the crap out of it and in the end it isn't that efficient as a result.
Low pressure turbos and twin low and high pressure turbos is to not only gain mpg, as these tests normally are done when the turbo is under littlw load thus benefiting fuel gains but also to change the nature of the turbo to ensure the lag element is also removed.
Problem with remaps on diesel engines is that you have to utilise a turbo which may not have been designed to cope with differing inputs and expect it to deal not only with more power, but give better fuel efficiency at the same time.
Add into this the fact that manufacturers nowadays are expected to achieve higher and higher mileages from such engines (rather than one off tunes which may only make the "standard" turbo last 15k miles) without issue.
This is where the challenges of the "new" engines are. Coming in with diesel remap is great but i expect in the grand scheme of things it can't meet the criteria which new engines are expected to reach, or tick as many boxes.