>Is a 800 MPG car possible?
There's a solar car competition that beat that target long ago. The Purdue University solar "Pulsar" car hit 4913 MPGe.
https://www.purdue.edu/uns/x/2009a/090506KingSolarcar.html
Extremely high energy efficiency has been attainable for a very long time, it's just that people expect more out of their vehicles to the point where the drivetrains and body designs can't keep up beyond marginal gains.
>MPGe
What the fuck is this meaningless unit.
Miles per gallon of electricity- P-bbb-FUCK OFF.
Complete nonsense. >Captcha KYS YHVM (KYS You Hugless Virgin Man)
Lol
Except it burned no petrol, in fact it burned nothing at all. It's a hydrogen fuel-cell vehicle, and it consumed a quantity of hydrogen with an energy content equivalent to about half an ounce of gasoline. OP asked about MPG and lean-burn engines, we're talking about burning fuel here. The Shell Eco-Marathon is deceiving anyway, the requirements and measurements don't translate to the real world. Their current record holder on GASOLINE is the La Joliverie MicroJolie, or MicroJoule. Managed 8870mpg American, about 10,600mpg Imperial, burning gasoline in an internal combustion engine, set the record in 2014 I believe.
Want to take advantage of waste heat from a combustion engine? Turbocharger. The best Stirling engines in the world are still only half as efficient as the engine in a production car, they're garbage. Best case scenario, absolute best case wherein you somehow capture 100% of the waste heat of an internal combustion engine and use it to power an impossibly good Stirling engine, you're boosting your total efficiency by 5%. 5% is the unrealistic and unachievable most you could ever hope for by adding a Stirling engine to utilize waste heat from an internal combustion engine. In the real world, that's going to translate to <1% gains. No, anon, just no.
No, heat definitely is an important factor. Both pressure ratio and temperature ratio are important to turbine performance. Enthalpy is the physics term, but you can think of it as the fact that a high pressure flow can do more work at a higher temperature than a lower one. The hot gasses are more voluminous and as they move through the turbine. More heat, greater volume for a given pressure. So if the temperature is higher at the inlet and the gasses cool as they exit, the pressure will decrease even more than a cooler gas flow. Evidence of this in practice is that the more advanced jet engines become the higher their turbine inlet temperature.
Hit the nail on the head with this one here. Any serious turbo-fag will tell you that back pressure isn't the real drive behind a turbo, it's temperature differential. Pressure implies restriction, but the goal is throughput, restrictions are always a bad thing. In an "ideal" turbocharged engine, there'd be effectively no pressure difference between the inlet and outlet of the turbine, only a massive difference in temperature between the inlet and outlet sides with hot exhaust expanding and cooling through the turbine, that way no power is wasted compressing exhaust gasses in the exhaust manifold/turbine housing.
Same thing applies on the intake side. >Why does it make less boost but more power with my new cams?
Because air is actually getting where it needs to go, not just being compressed into the manifold; you're making less pressure because you're getting more flow, more throughput, and that's the real goal.
No. And here's why. One gallon of gasoline contains 33.41kWh of energy. To go 800mi on that amount of energy you'd have to use 41.8Wh/mi of energy. 1hp is 745.7W, and you'll only get part of that wattage out as actual propulsion because some will always be lost as heat. Let's assume you want to go 20mph (3min per mile) at 100% efficiency. To go 1mi at 20mph with only 41.8Wh of energy you need to do it with 836W: 1.12hp.
>To go 1mi at 20mph with only 41.8Wh of energy you need to do it with 836W: 1.12hp.
My Ebike (DIY) gets 10 miles at 20mph (ave) at 48v 13AH w/ 1KW (full assist output/throttle), but realistically no motorized vehicle is less than 100lbs or light enough to not have diminishing returns to power output. The secret to why it can make nearly 10x the expected range is the fact a mid drive uses the bike chain drive. Electric vehicles so far don't have any sort of drive train, as the motor itself is the drive but the mouth breather electrical engineers don't think it's needed for anything speed related. So their "answer" is to increase the Volts of the power pack to maintain Higher Watts for RPMs and by doing so increases the weight of the platform. Everything related to speed and range begins to diminish from there, but now you have enough energy equivalent of a high explosive bomb under your seat do to lacking a single component that had allowed the automobile to leave the city in the first place.
Maybe... But then you have to deal with the extra weight. I don't know if I've seen regen breaks on a motorcycle.
>Removing the extra cost of adding a hybrid system to a cheap motorcycle, which is going to cost more than just paying for gas over 5 years
A 125cc motor is so close to what it is practically possible that adding a hybrid system would only help a little.
I've been experimenting with making a hydrogen/gasoline hybrid using a combination of GEET and electrolysis to produce the hydrogen on the fly from water. Electrolysis alone doesn't seem to produce enough hydrogen to make much of a difference and I haven't had much luck with the GEET yet. I made the mistake of jumping right to aircooled Volkswagen thinking I could make it work when all I've ever seen online is single cylinder lawnmower engines running off one. I'm going to take a step back and try to replicate that first before moving ahead.
Some dude in the 70s/80s used heating elements in his gas tank to create gas vapors and rigged a carbed V8 to run on the vapors and his fuck huge Cadillac was getting like 120mpg. It took like 45 secs to get to 60mph though. Do that shit to a small car like a mirage and you could probably get close to 800mpg. If anyone know who im talking about post a link. I cant find shit out that guy anymore.
On the topic of gas efficiency, I wonder how much better you could make an old car by swapping it's engine with a modern direct injection engine with a turbo. Modern engines are so efficient that they can keep hitting 20-30mpg as the cars get heavier, so what if we put the new inside the old? I'd like to see what an L15 inside an old CRX
If by car, you're willing to count single seat vehicles that are basically used like skeleton sleds that go really, really, slowly around a track meant for feet, then...
The answer's probably still no.
https://www.metacritic.com/tv/junkyard-wars/season-2/episode-5-mileage-marathon
Granted that was made of literal junk and decades ago, but I can't imagine pushing it more than 400.
Plenty of modern cars do stratified lean-burn bullshit for MPG. I know some Hondas push up to 22:1 afr which is god damned lean, only while idling or under very light load as I understand it. Anyone know of anything else that already exists, that's real and in production, that runs a leaner burn than 22:1? Not finding this well documented, just vague "yup everyone does this" with no numbers and no references.
The israelites don't want us driving efficient cars. Things really keep going down hill. In 10 years the average car will probably be half as efficient vs what we can buy today.
>Is a 800 MPG car possible?
There's a solar car competition that beat that target long ago. The Purdue University solar "Pulsar" car hit 4913 MPGe.
https://www.purdue.edu/uns/x/2009a/090506KingSolarcar.html
Extremely high energy efficiency has been attainable for a very long time, it's just that people expect more out of their vehicles to the point where the drivetrains and body designs can't keep up beyond marginal gains.
>MPGe
What the fuck is this meaningless unit.
Miles per gallon of electricity- P-bbb-FUCK OFF.
Complete nonsense.
>Captcha KYS YHVM (KYS You Hugless Virgin Man)
Lol
>MPGe
who the fuck cares.
0.01614 litres of petrol for 100 km (14,573 mpg)
https://www.guinnessworldrecords.com/world-records/most-fuel-efficient-vehicle
Except it burned no petrol, in fact it burned nothing at all. It's a hydrogen fuel-cell vehicle, and it consumed a quantity of hydrogen with an energy content equivalent to about half an ounce of gasoline. OP asked about MPG and lean-burn engines, we're talking about burning fuel here. The Shell Eco-Marathon is deceiving anyway, the requirements and measurements don't translate to the real world. Their current record holder on GASOLINE is the La Joliverie MicroJolie, or MicroJoule. Managed 8870mpg American, about 10,600mpg Imperial, burning gasoline in an internal combustion engine, set the record in 2014 I believe.
Hydrogen is fuel
Wasn't burned, not a combustion engine, no engine at all.
OK Austie. You win.
There's a car dude I watch on YT that put a lawnmower carb with his own arduino powered carb "tuner" that gets like 45mpg on a fucking V8.
Idk about converting DC electric to Miles per Gallons of Gasoline, but yeah
ICE wastes most of the energy of gasoline and diesel to heat.
Your mum.
I've been wondering - why can't an engine use its waste heat to power a secondary stirling engine, eliminating the drag of the alternator/ancillaries?
you are 14 years old
Your Mum was 14 when she farted you headfirst onto the pavement
thanks for confirming that you're underage
Thanks for confirming your Mum was underage when she was sexually destroyed by one of 6 or more men (we don't really know for certain).
Based anon angerer
Cringe mad at the internet
Have you ever seen a sterling engine? actually no torque and low RPM. They cannot be used to generate anything useful.
Yes, I've seen one. I've also seen a video of this one, powering an entire car with 50 or so horsepower.
Maybe use it to power accessories? Alternator, A/C compressor, etc.
Want to take advantage of waste heat from a combustion engine? Turbocharger. The best Stirling engines in the world are still only half as efficient as the engine in a production car, they're garbage. Best case scenario, absolute best case wherein you somehow capture 100% of the waste heat of an internal combustion engine and use it to power an impossibly good Stirling engine, you're boosting your total efficiency by 5%. 5% is the unrealistic and unachievable most you could ever hope for by adding a Stirling engine to utilize waste heat from an internal combustion engine. In the real world, that's going to translate to <1% gains. No, anon, just no.
It's a topic of research.
https://en.wikipedia.org/wiki/Exhaust_heat_recovery_system
>not having a 50cc pony motor to spool your 260mm turbine powered hydrogen shitbox
>Not having two Buick V8s coupled together just to start one engine on your SR71
Probably because the most efficient use of waste heat is to drive a turbo.
That's air pressure, not heat, surely?
No, heat definitely is an important factor. Both pressure ratio and temperature ratio are important to turbine performance. Enthalpy is the physics term, but you can think of it as the fact that a high pressure flow can do more work at a higher temperature than a lower one. The hot gasses are more voluminous and as they move through the turbine. More heat, greater volume for a given pressure. So if the temperature is higher at the inlet and the gasses cool as they exit, the pressure will decrease even more than a cooler gas flow. Evidence of this in practice is that the more advanced jet engines become the higher their turbine inlet temperature.
Hit the nail on the head with this one here. Any serious turbo-fag will tell you that back pressure isn't the real drive behind a turbo, it's temperature differential. Pressure implies restriction, but the goal is throughput, restrictions are always a bad thing. In an "ideal" turbocharged engine, there'd be effectively no pressure difference between the inlet and outlet of the turbine, only a massive difference in temperature between the inlet and outlet sides with hot exhaust expanding and cooling through the turbine, that way no power is wasted compressing exhaust gasses in the exhaust manifold/turbine housing.
Same thing applies on the intake side.
>Why does it make less boost but more power with my new cams?
Because air is actually getting where it needs to go, not just being compressed into the manifold; you're making less pressure because you're getting more flow, more throughput, and that's the real goal.
No. And here's why. One gallon of gasoline contains 33.41kWh of energy. To go 800mi on that amount of energy you'd have to use 41.8Wh/mi of energy. 1hp is 745.7W, and you'll only get part of that wattage out as actual propulsion because some will always be lost as heat. Let's assume you want to go 20mph (3min per mile) at 100% efficiency. To go 1mi at 20mph with only 41.8Wh of energy you need to do it with 836W: 1.12hp.
>To go 1mi at 20mph with only 41.8Wh of energy you need to do it with 836W: 1.12hp.
say no more
>recumbent ebike in a pod
>car
Somehow I get the feeling that you didn't read the OP. He said "CAR"
>To go 1mi at 20mph with only 41.8Wh of energy you need to do it with 836W: 1.12hp.
My Ebike (DIY) gets 10 miles at 20mph (ave) at 48v 13AH w/ 1KW (full assist output/throttle), but realistically no motorized vehicle is less than 100lbs or light enough to not have diminishing returns to power output. The secret to why it can make nearly 10x the expected range is the fact a mid drive uses the bike chain drive. Electric vehicles so far don't have any sort of drive train, as the motor itself is the drive but the mouth breather electrical engineers don't think it's needed for anything speed related. So their "answer" is to increase the Volts of the power pack to maintain Higher Watts for RPMs and by doing so increases the weight of the platform. Everything related to speed and range begins to diminish from there, but now you have enough energy equivalent of a high explosive bomb under your seat do to lacking a single component that had allowed the automobile to leave the city in the first place.
Honda we need this in the next grom
50cc scooters do like 150mpg max. There is no way in hell a 125cc will get 800mpg.
We'll never know unless honda goes crazy like they make an hcci 125cc hybrid.
Maybe... But then you have to deal with the extra weight. I don't know if I've seen regen breaks on a motorcycle.
>Removing the extra cost of adding a hybrid system to a cheap motorcycle, which is going to cost more than just paying for gas over 5 years
A 125cc motor is so close to what it is practically possible that adding a hybrid system would only help a little.
maybe going 800 miles down hill.
For a production car, Aptera is probably the closest to it. If they ever build them.
I've been experimenting with making a hydrogen/gasoline hybrid using a combination of GEET and electrolysis to produce the hydrogen on the fly from water. Electrolysis alone doesn't seem to produce enough hydrogen to make much of a difference and I haven't had much luck with the GEET yet. I made the mistake of jumping right to aircooled Volkswagen thinking I could make it work when all I've ever seen online is single cylinder lawnmower engines running off one. I'm going to take a step back and try to replicate that first before moving ahead.
Some dude in the 70s/80s used heating elements in his gas tank to create gas vapors and rigged a carbed V8 to run on the vapors and his fuck huge Cadillac was getting like 120mpg. It took like 45 secs to get to 60mph though. Do that shit to a small car like a mirage and you could probably get close to 800mpg. If anyone know who im talking about post a link. I cant find shit out that guy anymore.
On the topic of gas efficiency, I wonder how much better you could make an old car by swapping it's engine with a modern direct injection engine with a turbo. Modern engines are so efficient that they can keep hitting 20-30mpg as the cars get heavier, so what if we put the new inside the old? I'd like to see what an L15 inside an old CRX
Ford fiesta S was a 2500lb car and I consistently got 40 - 45mpg without being a stickler about it, just driving how I felt.
The Citroen 2CV had a stupid high MPG and very slow acceleration.
Also a very strong built boxer engine, and cushy suspension.
The frogs had it figured out 80-90 years ago. Maybe nearly 100 now.
If by car, you're willing to count single seat vehicles that are basically used like skeleton sleds that go really, really, slowly around a track meant for feet, then...
The answer's probably still no.
https://www.metacritic.com/tv/junkyard-wars/season-2/episode-5-mileage-marathon
Granted that was made of literal junk and decades ago, but I can't imagine pushing it more than 400.
I will eat my fucking arms if that's 70:1.
Don't say its impossible now.
(If you count hybrids)
Yeah
>make the road and wheels steel to reduce friction
>aero package
>maximum weight reduction
>small displacement diesel hybrid
Wa la
Plenty of modern cars do stratified lean-burn bullshit for MPG. I know some Hondas push up to 22:1 afr which is god damned lean, only while idling or under very light load as I understand it. Anyone know of anything else that already exists, that's real and in production, that runs a leaner burn than 22:1? Not finding this well documented, just vague "yup everyone does this" with no numbers and no references.
The israelites don't want us driving efficient cars. Things really keep going down hill. In 10 years the average car will probably be half as efficient vs what we can buy today.