10 replies to this topic

[StuffedBeaver]

What rate of MPG do F1 cars return. I've heard that it's about 4mpg.

Is that the case for all of them? or are there some really efficient ones that do about 5mpg?

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The Beav

[Limey]

Back in the 70's, I recall a figure of 5.3 mpg for a 3 liter Cosworth V8 which had an output of 500 bhp. Ferrari V12's of that era used more fuel. Today's cars with 800 - 900 bhp maybe the same if the engine management system is more efficient in utilising fuel but 4 mpg may be a reasonable assumption.

[Fritz]

A few years ago I heard the number of 1,6 kilometers per liter, which would mean about 6,4 mpg. It would seem reasonable to me that todays cars are less thirsty than the were when I heard aforementioned number (the 3,5 litre era).

[Fritz]

Sorry, I made a mistake. 1,6 km/l means 4 mpg. So today it must be that they consume a bit less then 4 mpg.

[Leo]

At the end of the turbo era, fuel tank size was restricted to around 200 liters for a 300 km race. We all can do the math (1.5km/l, or 3.5mpg). Since refueling stops have become legal again, fuel consumption has become (slightly) less important. Also turbo engines have a higher (theoretical) efficiency than atmosferic engines. So the actual fuel consumption nowadays may be in excess of 1.5km/l / 3.5mpg.

[Fritz]

I do not agree that fuel consumption is no longer as important as it was before. Starting with 10 l more means starting with 8 kg more... Why did Ferrari build a V10? Because the V12 was to thirsty.

[Leo]

I agree with you that fuel consumption is still very important. But in 1987/88 it was the no.1 priority, just to make it to the finish. These days you can gain some performance at the cost of fuel economy. Refueling stops will make you last the race anyway.

[Ray Bell]

There is an allied issue here - the fuel in F1 is not really like the fuel we buy for our street cars. It weighs more and is brewed for greater performance, while still coming within parameters laid down by the rulemakers.
This practice commenced during the 'fuel consumption' era mentioned above, so that engines could still produce the power while leaned off to go the distance.

[FordFan]

Can anyone explain what 'direct injection' is and how much and why it would supposedly improve gas mileage? There's been some talk about a couple of engine makers adopting this technology (Renault, Ford).

[Jonathan]

FordFan

Dont quote me on this. But I beleive Direct Injection implies some form of External Scavenging. The idea is as I understand it to do away with the the wasted "Compression Stoke" and to inject a pre-mix of air & Gas vapours on each upward piston stroke.

(I am recalling the "Orbital" 2-Stroke engine from the early 1990ies, where I first heard of this term...)

Perhaps someone else knows more than I do on this subject, however ?

[davo]

Orbital Engine Corporation is indeed a West Australian based company which develops and markets direction injection systems and engines.

It has a long and some what convoluted history but the direct injection fuel injection is now a commercial reality The company site is http://www.orbeng.com.au/

The direct of direct injection is to do with where the fuel is introduced into the system not the air. The air side of the engine is conventional. Low pressure fuel is metered into an injection chamber (in the head with a very small orifice to the combustion chamber) and then at the appropriate moment (after the valves or ports are closed) the fuel is atomised and introduced to the combustion chamber (this is the "direct" bit as opposed to port or throttle body type injection) with an unmetered by accurately timed blast of very high pressure air.

It can be used on 2 and 4 stroke engines and has been prototyped or commercially sold in cars, bikes, mopeds, and outboards.

Its advantages over convential systems are:

Low energy use (the fuel is metered at low pressure)
Excellent (read small particle) atomisation
Low emissions / low fuel consumption - little to no unburnt fuel out the exhaust
Improve air flow volumes due to not needing to carry heavy fuel in the air flow.
The possibilities of more radical port/valve timings due to some of the above.

Obviously any of these advantages would be attractive to F1 as they would be to commercial designers

My understanding is Mitsubishi among others are also working seriously on direct injection. Although I am not aware of any details.

BTW Ralph Sarich the founder of the Orbital company won inventor of the year in Australia some time in the mid 70s although his invention at that time and what is commercially and technically valuable now are not at all similar.