Details On Oerlikon Graziano 4-Speed Electric Drive Transmission


Oerlikon Graziano’s 4 SED (4 Speed Electric Drive) four speed transmission with two motors and no clutch is a trick device, which according to company could increase efficiency by 15%.

This 15% translates to more range or smaller battery pack at the same range.  However, a single-speed transmission is simple, reliable, light and less expensive, so it’s not an easy task for Oerlikon Graziano to convince car manufacturers to choose a 4 speed transmission instead of one for only a 15% gain in efficiency.

A prototype car, a Mercedes Vito minibus, with 4SED will be demonstrated at Cenex LCV 2014 from 10th to 11th September.

Oerlikon Graziano’s Head of Performance Automotive, Paolo Mantelli stated:

“We have been at the forefront of automotive transmission technology, since developing and supplying our first complete gearbox in 1996, and of the electric market, with the production of the first electric axle for the golf cart market. Together with our controlled company VOCIS Ltd, contributing state of the art control software, a variety of business opportunities and potential supplier-partners connections are opened. We intend to be a key partner developer/manufacturer of Zero Emissions Driveline Systems for all the OEMs playing in this increasingly relevant automotive sector.”

“Our focus is on developing integrated powertain solutions, aimed at maximizing performance and efficiency. 4SED is truly innovative, it is seamless, it is clutch less and it needs no synchronizer.”

No clutch, no synchronizer, but seamless and more efficient? The interesting thing is that 4SED has two smaller electric motors instead of one larger unit, which probably does not help to drive the costs down.

“Oerlikon Graziano’s four-speed seamless shift electric transmission – called 4SED – has a very simple design. By using two small electric motors instead of a single large unit, and by providing four ratios, the motors run close to their peak efficiency for more of the time, and shifts are accomplished without interrupting the drive. Overall energy consumption is reduced by up to 15 percent compared to a single-speed transmission, which translates into increased range or improved performance. The technology is scalable to suit a wide range of different vehicle types, urban electric cars, high performance cars, hybrid 4WD applications, electric city buses and trucks. It is suitable also for applications with 48V motors, allowing significant cost savings and reducing risks of high voltage.”

“4SED has been fitted to an electric Mercedes Vito minibus demonstrator and is currently touring renowned European vehicle manufacturers and events to showcase its unique features. Initial customer feedback is very positive, especially for its smoothness in the shifting function and its wide scalability through different platforms and performance requirements.”

Oerlikon Graziano 4 SED (4 Speed Electric Drive)

Oerlikon Graziano 4 SED (4 Speed Electric Drive)

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20 responses to "Details On Oerlikon Graziano 4-Speed Electric Drive Transmission"
  1. Mike I says:

    This setup has a total gear ratio from 6.9:1 to 20:1. Definitely still a low speed system. For reference, Tesla uses 9.71:1 in their single speed reduction on the Model S.

  2. Mikael says:

    No! Bad dog! No pooping on the floor!

    We finally cleaned up and got rid of extra things that cost, weighs and breaks and now they want to put them back?

    Battery improvements is all needed to get better range and better efficiency.

    1. arne-nl says:

      If you are in the business of selling gearboxes, what else can you do? Their livelihood is on the line.

      But don’t worry, if a gearbox adds range at a lower cost than a bigger battery, and can be guaranteed to function for the life of the car without maintenance, I am the first to say: who cares?

      Let the law of survival of the fittest deal with this. If it’s a good solution if will survive, otherwise, it will die.

  3. Rich says:

    “However, a single-speed transmission is simple, reliable, light and less expensive,”


    “so it’s not an easy task for Oerlikon Graziano to convince car manufacturers to choose a 4 speed transmission instead of one for only a 15% gain in efficiency.”
    These statements assume “simple, reliable, light and less expensive” are the highest priorities of the auto manufacturers. Introducing complexity and expense to a product for the sake of post-sale maintenance and parts revenue seem to be Pro Quo these days. IMO. I hope your right and “simple, reliable, light and less expensive” are the governing decision criteria.

  4. Rob Stark says:

    The reason auto companies introduced 8 speed transmissions is to meet CAFE standards without reducing horsepower and performance.

    That is not an issue for BEVs.

    Added repairs hurts the OEM bottom line as they are claims against warranties.

    Rebuilding transmissions at AMCO for 10+ year old cars does not help the bottom line of OEMs.

  5. ggpa says:

    A 15% claimed improvement (and I have my doubts) is not enough to justify a lot of extra parts and weight and complexity when you are detailing with a light passenger EV.

    But it is an interesting concept and it might be more useful for hybrids or heavy duty EVs.

    1. Spec9 says:

      It might be. Especially if you are build an EV with a very big battery to get a long range. But I am also very skeptical. But I’ll keep an open mind and want to see independent testing.

    2. sven says:

      But wouldn’t a corresponding 15% reduction in CO2 be enough to justify the the extra parts, weight, and complexity.

      1. ggpa says:

        I’m not sure how to estimate the CO2 savings, but if a Leaf generally uses $30 to $40 / month in electricity, then a 15% savings (if true) is modest. If I guess what this upgrade costs then the ROI looks weak.

    3. ggpa says:

      spec9 / sven

      I am not sure this will save 15%, but lets ignore that for now.

      Perhaps an example will clarify this for you. A Leaf battery costs $6500. So a 15% bigger battery (with all else equal) costs $1000 more, and adds about 100 pounds to the car weight.

      So if Nissan wanted to upgrade the Leaf range, they could spend $1000 on a bigger battery, or add this transmission and switch to two motors.

      I very much doubt they can add the transmission and second motor for $1000.

      On the other hand … if you are building a heavy duty commercial delivery vehicle with a $50000 battery, then a 15% saving is a much larger bounty.

      Or if you are building a hybrid car, then this transmission might be cheaper than the planetary transmission that Toyota, Ford, Chevy currently use in their hybrids.

      1. sven says:

        Cost and reliability will be very important factors. However, a 15% improvement in efficiecy is nothing to sneeze at. There are some downsides to putting a bigger battery into the Leaf. A bigger battery would take up more space and take longer to charge. As battery prices come down and bigger batteries get stuffed into EVs, space consumed and charging time will become more important factors and a 15% improvement in efficiency won’t seem as trivial as it does now.

  6. Chris O says:

    The electric motors don’t have the sort of power people have come to expect in vehicles. If they did they would probably tear the transmission to pieces.

    Maybe Tesla’s approach for Model X is better: 2 motors on two different axles that engage at different speeds to improve efficiency.

    1. ggpa says:

      This is interesting “Tesla’s approach for Model X … 2 motors on two different axles that engage at different speeds to improve efficiency.”

      Can you add (or link to) more details please?

  7. Just like a gasoline car, the transmission will keep the electric motor nearest to its ideal RPM for either power or efficiency, Unfortunately, electric motors are already extremely efficient compared to any gasoline engine, so there are diminishing returns with a transmission (extra weight, complexity, cost, maintenance). It’s no surprise that zero manufacturers currently offer a transmission in an pure EV.

    Electric cars are already far heavier than their equivalent oil burning counterpart, and far more expensive, therefore I don’t see a transmission in anything except the highest cost electric cars, like a Tesla.

    No surprise, Tesla originally sold the Roadster with a two speed transmission, but it had some big durability problems. They removed the two speed from ALL the original Roadsters and replaced them with the current reduction gear box with a 9:8 ratio.

    Of course a transmission can be built that can be durable… heck, diesel trucks with well over 2000 foot pounds of torque that drive a million miles do just fine. But, those trucks, like cars, absolutely NEED a transmission. Electrics don’t.

    One other issue… oil engines not only have a far narrower power band than an electric, but they are RPM limited compared to an electric. I think the Tesla spins the motor at 16,000 RPM at 130 mph, something a typical oil engine cannot do. For anybody to make an electric “supercar” that can go 200mph, it will have a transmission. Guaranteed.

  8. Richard Gozinya says:

    It’s funny to see people who are advocates of EVs complaining about weight and cost, then turning around and saying we just need bigger batteries. As for maintenance, reliability and weight issues. Modern transmissions are very reliable, and from the looks of things, far more reliable than Tesla’s drivetrain, which seems to be built to break.

    1. Spec9 says:

      Wrong. We are open to the idea, we are just skeptical of the transmission maker’s claims. There is probably a reason why none of the pure EVs on the market have a transmission. If the 15% efficiency claims are true, it may make sense in certain EVs. However, that is going to require the transmission to cost less than the 15% of battery sized saved.

      1. Richard Gozinya says:

        Actually the reason Tesla didn’t put a multi-speed gearbox into their cars is that they couldn’t manage to build one that wouldn’t break. And the Brammo Empulse does in fact have a six speed gearbox, so it’s not unprecedented.

  9. Spec9 says:

    I’m quite skeptical that they can really get a 15% efficiency improvement by adding a transmission. But I’ll try to keep an open mind. If they really get a 15% improvement in efficiency and the transmission is not very expensive to build, it MIGHT make sense in that it reduces the amount of batteries (and thus cost) to get a good range. But I’m very skeptical. Thorough testing required.

  10. Phr3d says:

    I am attracted to the two-motor idea, in that a smaller motor to maintain speed appeals to my logic, but as spec9 mentioned, minds much better than mine have already discounted that idea..
    two smaller motors, with only one being used for actual acceleration Seems like a good plan, and they can swap constantly for balanced life.

  11. Bill Howland says:


    Perhaps in the coming days they can flesh out precisely why they are claiming a 15% improvement. Especially interesting since these 100 horsepower – class units are just the right power level for a vast array of vehicles which are good candidates for electrification.

    I disagree that simpler is better, in view of the 13% replacement of the very simple Tesla Drives. After all, the Volt scheme is complicated, but like the Prius Synergy Drive (I believe designed all by the same Toyota subsidiary), it is proving itself by the test of Time. This company obviously knows what corners not to cut, and has the intelligence and manufacturing prowess to also know the very important fact that they are *not* cutting corners, even accidentally.