Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - How much power does it take to spin a 1.0l geo engine?

GreenHornet · 02-17-2013, 06:53 PM

Hey Stubby,

You are looking at a common parallel hybrid configuration here. What you want to do is what Honda does with there insight. You need enough E-motor torque to run the car on its own. As the E-motor will also be adding to the ICE when needed for higher acceleration of hill climbing.

So you figure this out by determining your speed needs. This will give you an idea of the power you will need in your E-Motor always round up HP as you will need roughly 10-15% more in order to balance gear train mechanical losses.

With a geo metro sedan if stock you would have roughly these specs!

Coef Drag = .32
Frontal area = 19.5
Curb weight = 1,694lbs
Speed = 65mph

So with these inputs you would need 11.5 HP = 8.57kw to cruise at 65mph. However this is not really accurate because you will add weight to the car while hybridizing it and again mechanical losses. I would use 12kw continuous and 30kw peak or around 40hp peak motor output for a car this size and going at a steady cruise with ICE augmentation. What you need here is solid low end torque and a solid RPM range up to like 5000 RPM

Now depending on how you do your gearing as well as tire selection this will have a major impact on your overall top performance. Go for low 1st and 2nd gear ratios like in the 4.1 range with super high final drive ratio like in the .60 range this will give you good around town E drive ability and excellent freeway cruise economy! You would have better acceleration than original Metro and better fuel economy with this plan. I think stock gear in 1st for metro is like a 3.42 with a 5th gear of like .76!

Its always better to go with a custom box if price is not an issue. With the right E-Motor you can stick with the stock tranny and go with the highest final drive ratio avail for the Metro which I believe is the 3.524. The E-motor will offset this sluggish ride of the 1.0L ICE with this gear ratio selection. This gear ratio was not avail in the US and was only on the larger 1.3L engines I believe however I do think its possible to swap the gears however I would double check it to be sure as I am not 100% on that.

Good luck Stubby,

GreenHornet

02-17-2013, 06:53 PM	#9 (permalink)
GreenHornet Master EcoModder Join Date: Feb 2013 Location: Oregon Posts: 429 Thanks: 41 Thanked 108 Times in 68 Posts	Hey Stubby, You are looking at a common parallel hybrid configuration here. What you want to do is what Honda does with there insight. You need enough E-motor torque to run the car on its own. As the E-motor will also be adding to the ICE when needed for higher acceleration of hill climbing. So you figure this out by determining your speed needs. This will give you an idea of the power you will need in your E-Motor always round up HP as you will need roughly 10-15% more in order to balance gear train mechanical losses. With a geo metro sedan if stock you would have roughly these specs! Coef Drag = .32 Frontal area = 19.5 Curb weight = 1,694lbs Speed = 65mph So with these inputs you would need 11.5 HP = 8.57kw to cruise at 65mph. However this is not really accurate because you will add weight to the car while hybridizing it and again mechanical losses. I would use 12kw continuous and 30kw peak or around 40hp peak motor output for a car this size and going at a steady cruise with ICE augmentation. What you need here is solid low end torque and a solid RPM range up to like 5000 RPM Now depending on how you do your gearing as well as tire selection this will have a major impact on your overall top performance. Go for low 1st and 2nd gear ratios like in the 4.1 range with super high final drive ratio like in the .60 range this will give you good around town E drive ability and excellent freeway cruise economy! You would have better acceleration than original Metro and better fuel economy with this plan. I think stock gear in 1st for metro is like a 3.42 with a 5th gear of like .76! Its always better to go with a custom box if price is not an issue. With the right E-Motor you can stick with the stock tranny and go with the highest final drive ratio avail for the Metro which I believe is the 3.524. The E-motor will offset this sluggish ride of the 1.0L ICE with this gear ratio selection. This gear ratio was not avail in the US and was only on the larger 1.3L engines I believe however I do think its possible to swap the gears however I would double check it to be sure as I am not 100% on that. Good luck Stubby, GreenHornet