- 2014 max boost levels are likely to be higher than 2.5 bar (Renault suggests 3.5 bar as a maximum)
Once you're in boost territory, those kind of gaps have very little impact on fuel efficiency
- Aerodynamic changes in the last ~25 years mean you can't assume the overall drag and drag/lift ratios of the 1988 and 2014 cars will be close enough to be comparable. Obviously the drag level plays a large role in fuel consumption.
Eh. No. The engine has NO idea it's even in a car. The drag level has zero impact on the peak power output of an engine. Irrelevant
- Cylinder deactivation/cut was not employed in the 1988 Honda engine (AFAIK). In 2014 cylinder cut will be used even more aggressively than it has been in previous years, due to the reduced requirement for exhaust blowing.
Those things never happen at full load. Never happen at peak power. Irrelevant.
- The 2014 engines use direct fuel injection (fuel efficiency improvement).
Yes. major improvement. 40%? Not so sure. I can look more into it
- The 2014 power units will use the MGU-H to spool the turbo, reducing the need to waste fuel spooling it as was done with the twin Honda turbos.
At peak power you are not "wasting fuel to spool the turbo". You are at peak power the turbine is spinning well enough already
- You have assumed that fuel flow rate has a perfectly linear relationship with maximum output power ("611 / 1.29 = 473 bhp")
You don't get the equation. I was reporting the 129 kg/hr at peak power from 1988 to the 100 kg/hr of 2014. No linearity involved here.
- Rather than having a wastegate as a means of dumping excess boost pressure this will be recovered by power unit.
zero impact on peak power output. Irrelevant
- We don't know enough about the properties of the tyres (e.g. rolling resistance) to compare them like for like.
Tyres really ? zero impact on peak power. Irrelevant.
- There have, of course, been improvements in manufacturing (better precision in engine parts, better tolerances), lubricants and fuel in the last 25+ years.
Yes. Fuel probably has a bit more energy per kg. Better lubricants, better parts less friction and all, yes. 40%? Not so sure.
You took a bunch of things that will affect fuel consumption over a race and tried to break apart my peak power comparison. None of these things affect the peak power output of an engine. Two of your bullets make sense, the rest makes me think you have no idea what I'm trying to show here