Modern Turbocharging Power Torque And Fuel Economy, How?

[Richard]

I'm sure the nostalgia is heartwarming because every generation in history has said the old days were the best, but is there any chance of getting back on topic please?

For example the base level Ford Focus now has a 1.0l 3 cylinder engine with 100 or 125 bhp. This replaces a 1.6l 4cylinder engine with 100 hp.

[J.A.W.]

I'm sure the nostalgia is heartwarming because every generation in history has said the old days were the best, but is there any chance of getting back on topic please?

For example the base level Ford Focus now has a 1.0l 3 cylinder engine with 100 or 125 bhp. This replaces a 1.6l 4cylinder engine with 100 hp.

Can you put up the dyno curves of those two?
This will show a useful power-band comparison of torque vs rpm at regular road speeds..

[ChrisM40]

Its seems to me that the manufacturers are very clever about the way they 'tune' these modern fuel economy small turbos. While they can deliver the economy if driven exactly like government testing systems test, no one actually drives like that.

Im not known for being especially sympathetic on cars from an economy point of view and get nowhere near the economy they claim, not even close. In fact i get worse economy out of the company eco boost fiesta than I did out of my old 90s 1.6 Honda twin cam, an engine not known for its economy even then.

[Tommy Cookers]

.... if driven exactly like government testing systems test, no one actually drives like that.

cars have progressed to reduce aerodynamic drag and reduce engine losses but have become heavier for various reasons
heavier means their mechanical drag aka rolling resistance has increased, also the tyres are wider
toe works by increasing rr (but is fiddled in the tests)
wide tyres have a much higher rr in corners (but the tests ignore cornering)

rr is relatively large in real driving at urban speeds, but the tests are unrepresentative in this regard
so these tests are even more flattering today than they were eg 30 years ago

[Richard]

If only there was independent economy testing like NCAP.

[NoDivergence]

Its seems to me that the manufacturers are very clever about the way they 'tune' these modern fuel economy small turbos. While they can deliver the economy if driven exactly like government testing systems test, no one actually drives like that.

Im not known for being especially sympathetic on cars from an economy point of view and get nowhere near the economy they claim, not even close. In fact i get worse economy out of the company eco boost fiesta than I did out of my old 90s 1.6 Honda twin cam, an engine not known for its economy even then.

My Dad used to get 36-37 mpg from that motor. It was known for good mileage.

[mrluke]

Why would a car company not tune their economy to suit the test? No point making your car do 50mpg in real world but have to advertise it as 28mpg.

[J.A.W.]

This current French take on the subject includes a dyno chart..

http://www.psa-peugeot-citroen.com/en/a ... generation

[Powerslide]

Other than mechanical reduction, can there actually be a plot with a case of having an engine with more variation in the same sense as to say, its nigh impossible to get a big engine to do things a small engine can do at low demand, in this case low fuel usage rates yet with turbocharge, now there is access for small engine to do things big engines can do while also able to remain economical on low demand. Of course, even on high power demands it would still be more efficient but the variations seem to play a significant role in turbocharging a small engine and everyday practicality at the same time putting nice numbers on brochures.

[Powerslide]

This current French take on the subject includes a dyno chart..

http://www.psa-peugeot-citroen.com/en/a ... generation

Thank you, nice find

[ChrisM40]

Its seems to me that the manufacturers are very clever about the way they 'tune' these modern fuel economy small turbos. While they can deliver the economy if driven exactly like government testing systems test, no one actually drives like that.

Im not known for being especially sympathetic on cars from an economy point of view and get nowhere near the economy they claim, not even close. In fact i get worse economy out of the company eco boost fiesta than I did out of my old 90s 1.6 Honda twin cam, an engine not known for its economy even then.

My Dad used to get 36-37 mpg from that motor. It was known for good mileage.

Sorry to reply 4 months later, but if we are talking the D series and B series then no they werent good for economy, at all. They were pokey engines giving great performance, but they had among the worse economy figures. I usually got low to mid 20s.