Cheeky question about the new V6 engine efficiency

[user001]

Is there any knowledge floating around, what the reduction in fuel consumption or better efficiency would have been if the old V8 engines would have been limited to 11000 RPM? Very importantly bearing in mind that the old car's where about 50 kg lighter than the new ones.

Simply put: The old engines without the new MGU stuff so forth with the old weight.

Would there be the same reduction roundabout 30% possible?

cheers

[Lycoming]

You could probably reduce fuel consumption as much or more by dropping the rev limit. But you'd also drop power by about the same amount. The turbo formula is a bit more efficient, so power doesn't drop by as much as fuel consumption does.

Although ultimately, you could just force them to reduce fuel consumption regardless of engine formula by mandating tank size or, as they are now doing, limiting fuel flow rate.

[beelsebob]

No, you couldn't make 40% thermally efficient engines without a turbo. At least, no one's done it yet.

You also couldn't make engines that efficient without more modern designs than the V8s.

[FW17]

If the cars were not set to a minimum of 690 KGS and there was a choice of running the old v8 with the same fuel flow I doubt there being any advantage to running a turbo config.

[Tommy Cookers]

Is there any knowledge floating around, what the reduction in fuel consumption or better efficiency would have been if the old V8 engines would have been limited to 11000 RPM? Very importantly bearing in mind that the old car's where about 50 kg lighter than the new ones.
Simply put: The old engines without the new MGU stuff so forth with the old weight.
Would there be the same reduction roundabout 30% possible?

the old V8s have a huge bore:stroke ratio, chosen to enable 20000 rpm
for 11000 rpm they could be redesigned to a lower b:s ratio ideal for that rpm
this would greatly reduce area exposed to combustion heat, so greatly reducing the excessive energy lost to coolant
and allow higher compression ratio (which was stated to be limited by the large valve 'cutaway' volume)
and of course they ran up to 22% rich (simply throwing away much of the fuel)
and the fuel was not so optimised for energy/kg as the 2014 fuel is
IMO they (N/A engines) could have got quite close to the magic 30%, but were not given the chance
high-pressure direct injection was banned (enraging BMW and Cosworth)
anything like exhaust recovery was banned long ago

since 1958 F1 has run on fuel limited to road fuel Octane number
now F1 Octane number is unlimited
without this fiddle the 2014 engines could not reach the magic 30%
because their CR would need to be much lower