Sustainable fuels for 2026. V10's will be green!

[johnny comelately]

On the pitch and harmonics thing does anyone remember the story about the first Honda F1 car being fired up for the first time and it collapsing?

[Hoffman900]

You’ll never see the return of naturally aspirated engines under the fuel flow rules. You make power with a naturally aspirated engine with an excess of fuel, to make up for air you can’t push in from the atmosphere. If it’s an air restrictor engine, this is doubly so.

Turbos / forced induction are the only way you can make good power with limited fuel flow, and you do it by making the engine very knock resistant.

As for the 100 bar injection rules, that was because there was a development war with fuel pumps and other parts. Every time they raised the port injection pressure, it made more power. Honda has this well documented in one of their white papers from 2010. The FIA did it to control costs and reign in engine power gains (make more power / raise the ceiling, it requires a cascade of other development, and such is the development cycle).

If you want a good side-by-side of how the two types (naturally aspirated and a fuel flow restricted downsized turbo engine) are efficiency wise, check out Race Engine Technology Issue 136 about Audi’s DTM engines. The peak brake thermal efficiency of the NA V8 was about 36.5% where the turbo DI engine is 42%. It’s no contest.

I love naturally aspirated engines and the sound, but this is a pipe dream. Sorry, guys.

[vorticism]

There is no BMW direct injection V10 as far as I know. And im a BMW fan.

Your credentials notwithstanding, Mario Thiessen published a paper years ago which gave some details of the p85 prototype engine which was developed for 2005 and unused, claiming they had developed a combined port and direct injection system for it.

[vorticism]

You’ll never see the return of naturally aspirated engines under the fuel flow rules.

I don't think it's been suggested to maintain them.

If you want a good side-by-side of how the two types (naturally aspirated and a fuel flow restricted downsized turbo engine) are efficiency wise, check out Race Engine Technology Issue 136 about Audi’s DTM engines. The peak brake thermal efficiency of the NA V8 was about 36.5% where the turbo DI engine is 42%. It’s no contest. I love naturally aspirated engines and the sound, but this is a pipe dream. Sorry, guys.

Those are values in a vacuum; they playing second fiddle to F1's mandated aesthetics. That' the point of my line of arguing as it relates to the aesthetics of the engine. What's the drag value of four .2 cu m cylinders at 200 kph? How does the strength:weight ratio of a curved and cantilevered endplate compare to a planar endplate? Also the weight of the hybrid turbo system did little if anything to offset its reduction in fuel weight. You need to include power:weight among your metrics which determine pipe dreaminess.

[ENGINE TUNER]

Remember. They "only" needed 160kg for the whole race because they were so much lighter.
I think if you added TJI direct injection and today's low friction designs plus KERS they might even need less than 100kg of fuel!

Direct injection doesn't work well past 12k rpm. KERs must be powered, mguh is the perfect combo to KERS, but it turns the wasted engine noise into electrical power, you noise worshippers don't like that. The low friction is because you have 6 pistons instead of 10, and those 6 pistons are moving around 11k rpm rather than 18k rpm.

There is never a way that v10 will use less fuel than current PU, unless it is making drastically less power. Again, it must be repeated, in 1988 the 1.5L turbo cars were both fuel(195L) and boost(2.5 bars) limited against 3.5L unlimited engines and still the turbo cars won every single race. Asking for v10s back is like asking for carburation back, it is absurd and backwards, just for the sake of noise.

If the new electrification rules for 2026 are said to reduce fuel demand by 20% to 30%...
Combine that with the technolgoy... I definitely could see the V10 engines coming down to the 100kg per hour.

I know you are speaking for a practical standpoint but F1 has a way of rewriting the book on things!

As a side note the engines in the Gordon Murrary T50 and the Aston Valkyrie are interesting ones to watch for how efficient or not they are when you compare them to curretn Ferrari and Lamborghini NA V12 engines.

Where is this energy coming from? The ice will have less fuel and they are not recovering from the mguh anymore, so where is this energy coming from? They certainly can not make up for the loss of mguh with more mguk brake harvesting, and the new fuel will not be much more energy dense than the current one.
There is a alot of bogus talk going on.

[ENGINE TUNER]

There is no BMW direct injection V10 as far as I know. And im a BMW fan.

Your credentials notwithstanding, Mario Thiessen published a paper years ago which gave some details of the p85 prototype engine which was developed for 2005 and unused, claiming they had developed a combined port and direct injection system for it.

From my memory, anything other than port injection was specifically banned by the regulations back then.

[ENGINE TUNER]

You’ll never see the return of naturally aspirated engines under the fuel flow rules.

I don't think it's been suggested to maintain them.

If you want a good side-by-side of how the two types (naturally aspirated and a fuel flow restricted downsized turbo engine) are efficiency wise, check out Race Engine Technology Issue 136 about Audi’s DTM engines. The peak brake thermal efficiency of the NA V8 was about 36.5% where the turbo DI engine is 42%. It’s no contest. I love naturally aspirated engines and the sound, but this is a pipe dream. Sorry, guys.

Those are values in a vacuum; they playing second fiddle to F1's mandated aesthetics. That' the point of my line of arguing as it relates to the aesthetics of the engine. What's the drag value of four .2 cu m cylinders at 200 kph? How does the strength:weight ratio of a curved and cantilevered endplate compare to a planar endplate? Also the weight of the hybrid turbo system did little if anything to offset its reduction in fuel weight. You need to include power:weight among your metrics which determine pipe dreaminess.

On the start grid, the 2014 W05 weighed less than the 2013 W04

[vorticism]

Conceptually: reduce the cylinder size, increase the cylinder count, maintain peak cylinder pressure, raise upper RPM fuel flow limit and maintain current air mass flow from a turbocharger, to force a higher operating engine speed while maintaining current combustion philosophy. Greater losses to friction and pumping although not untenable; remember this is an aesthetics driven formula which eshews wheel fairings and mandates styling measures in the bodywork. Engine styling would not be out of place.

That or convert the V6s to two stroke operation.

You’ll never see the return of naturally aspirated engines under the fuel flow rules.

I don't think it's been suggested to maintain them.

If you want a good side-by-side of how the two types (naturally aspirated and a fuel flow restricted downsized turbo engine) are efficiency wise, check out Race Engine Technology Issue 136 about Audi’s DTM engines. The peak brake thermal efficiency of the NA V8 was about 36.5% where the turbo DI engine is 42%. It’s no contest. I love naturally aspirated engines and the sound, but this is a pipe dream. Sorry, guys.

Those are values in a vacuum; they playing second fiddle to F1's mandated aesthetics. That' the point of my line of arguing as it relates to the aesthetics of the engine. What's the drag value of four .2 cu m cylinders at 200 kph? How does the strength:weight ratio of a curved and cantilevered endplate compare to a planar endplate? Also the weight of the hybrid turbo system did little if anything to offset its reduction in fuel weight. You need to include power:weight among your metrics which determine pipe dreaminess.

On the start grid, the 2014 W05 weighed less than the 2013 W04

Right but at the end of the race the W04 was 50 kilos lighter. Wikipedia lists 691 kg vs 642 kg respectively, presumably dry weight.

[PlatinumZealot]

The major point of friction is the piston rings. The Turbo engines have more fancy piston rings because of the peak pressures, and likely had more in quantity per cylinder (need to check).. The v10 has hair thin piston rings, and like two of them per cylinder. It is hard to say if this was more friction like for like. More cams and valve springs yes... but technology. It might not be a significant difference in friction if you built an NA v10 today.

[Tommy Cookers]

in the archetypal NA 'high-revving V10' .....
piston friction is higher with the very high inertia loads at these high rpm
heat necessarily taken by coolant is higher due to the greater surface area of the larger-bore combustion chambers etc

traditionally a forced induction engine needed to have a lower compression ratio than NA would ...
but now F1 controls combustion rate in real time by injection variation in the microsecond region
so CR has become (equally) high for either type of engine
(complicated though with the Atkinson & Miller cycle effects)

[vorticism]

Mario Thiessen published a paper years ago which gave some details of the p85 prototype engine which was developed for 2005 and unused, claiming they had developed a combined port and direct injection system for it.

From my memory, anything other than port injection was specifically banned by the regulations back then.

It wasn't. In 2005 engine longevity rules were added and peak fuel pressure was specified, so they ditched the P85 concept and developed the P84/5 instead.

[Hoffman900]

in the archetypal NA 'high-revving V10' .....
piston friction is higher with the very high inertia loads at these high rpm
heat necessarily taken by coolant is higher due to the greater surface area of the larger-bore combustion chambers etc

traditionally a forced induction engine needed to have a lower compression ratio than NA would ...
but now F1 controls combustion rate in real time by injection variation in the microsecond region
so CR has become (equally) high for either type of engine

It's this and a MUCH better understanding of tumble / mixture motion in the cylinder.

[PlatinumZealot]

in the archetypal NA 'high-revving V10' .....
piston friction is higher with the very high inertia loads at these high rpm
heat necessarily taken by coolant is higher due to the greater surface area of the larger-bore combustion chambers etc

traditionally a forced induction engine needed to have a lower compression ratio than NA would ...
but now F1 controls combustion rate in real time by injection variation in the microsecond region
so CR has become (equally) high for either type of engine

The highest load on the rings are a function of the average pressure NEAR tdc. Speed near TDC is a good thing because hydrodynamic lubrication mainatains longer before the piston stops and reverses. Its doesn't care for the compression ratio. It only sees that pressure it's trying to hold near TDC when the lubrication boundary is mixed (part metal to metal , part oil boundary).

We will have to look at the piston speeds during the cycle of the V6 and the V10... But we cannot simply say the ring friction in the V10 is higher just be cause it revs higher. Have to break down what happens at TDC and what happens when the piston is sliding upward.

[taperoo2k]

But much of the efficiency gain is not in the combustion chamber, it's in recovering as much of the energy that comes out of the exhaust ports as possible. A V10 isn't going to be anywhere near the overall efficiency of a current, complicated, hybrid system.

What?!!

The PUs are 50% efficient overall. The ICE part alone isn't. Strip off the energy recover systems and you'd lose a huge chunk of that headline efficiency straight away.

It's reached 52% now, compared to an average petrol engine which is around 20% or so. Dropping the MGU-H and unrestricting the MGU-K should see more gains made for the 2026 PU's. It remains to be seen if synthetic fuels will be viable outside of motorsport. Your not putting any more additional carbon into the atmosphere depending on the method used to produce synthetic fuels but you still have to contend with air pollution.

As much as I love the V10's sound, I doubt we'll see them return in F1 anytime soon. Even if you coupled them with hybrid systems they probably wouldn't be as efficient as the current PU's without a lot of R&D investment chucked at it.

[Tommy Cookers]

It's reached 52% now ...Dropping the MGU-H and unrestricting the MGU-K should see more gains made for the 2026 PU's.

the thermal efficiency of the PU cannot be increased by enlarging the MGU-K
because recovery of actual kinetic energy isn't part of the 52%

the K machine only contributes to (WOT) PU performance when motoring the crankshaft on electricity from G-H action