I maybe starting a technical arguement, but does anyone know the RPM specs for the electric motor? For example, what RPM is it running at 65mph? What is the electric motors max RPM? I use the electric mode to climb hills on the freeway, but it is concerning if I’m high revving the electric motor under a load on a regular basis.
Not a technical response but: Is this a problem? Car is a) built to do this, b) there isn’t any other option, really (except to drive slower).
Addendum to my post above: Not being flip, but just not sure what you are concerned about. As I understand it: There’s no variable mechanical gearing, so motor rpm is always going to be proportional to wheel rpm (and car speed). “Max rpm” of the motor therefore occurs at max speed of the car. (Though could be rated higher). What about load? Going up hills means more load than on the flat. But (putting aside rare condition where engine drives wheels directly via the clutch, that you can’t select or control): if the load requires more power than the battery can supply, the engine kicks on and generates additional current to supplement the battery’s current. Regardless, the motor still drives the wheels snd so all the load is experienced by the motor*. This is true no matter what “mode” you are in. HV, EV etc mode don’t change this and the electric motor can’t tell what mode you are in. The mode just changes how current flows between the battery, motor, and engine/generator. http://www.evs27.org/download.php?f=defpresentations/EVS27-3A-5430337.pdf * up to 181 hp, which is the max hp of the motor. Total system is rated 212 hp. This forum speculates that at very high loads the engine is mechanically coupled directly to the wheels again to provide that last bit of power...even if it means running the engine at an inefficient rpm. This last case, the “full speed ahead/mechanical driving” is not the same as when the engine comes on to drive the generator to supply extra current that the battery cannot, which is the case described above.
How fast is the electric motor spinning at 101 mph? Car and Driver wrote that the Clarity has a governor that limits its top speed to 101 mph. Achieving that speed must require the car's full 212-hp potential, meaning the Engine Drive clutch is engaged to combine the power of the traction motor and the engine. Somebody, quick, jump in your Clarity and check this out. Thanks.
RPM of any component is of no concern to the user of the Clarity. It is fine to drive up to top speed, the low top speed of 101 is easily covered by the engine (only needs like 70 hp on flat ground to go that fast). Electric motors can't over-rev. The motor in the Clarity has a max speed set by the frequency put out by the motor controller and physical design of motor, and that also limits the top speed of the car. It doesn't have valves or pistons that are physically limited by movements and inertia at high RPM. They are less efficient at certain RPMs which is why the car has different modes of operation. If battery gets hot hill climbing the car will start the engine for assistance. Going up a long steep mountain pass at 80 mph the car only went 5 mins or less before the engine started even though I was under the blue power arc indicator on dash. The gas engine can drive the wheels mechanically (direct overdrive gear) or electrically (eCVT, electronic variator). If you go to the powerflow display, if the gear lights up between the engine and battery/between wheels the clutch is engaged meaning engine is physically driving wheels (most efficient mode at higher speeds). In eCVT mode the RPM of gas engine is selected based on load (which might be charging the battery so can be high RPM at at 0 mph, aka "angry bees" in rare cases). In mechanical overdrive, engine RPM is based on wheel speed, but this mode is only selected by computer in situations where it is safe and more efficient to do so. Bottom line is the car worries about protecting itself, you just have to drive. If you dramatically exceed design constraints of car, you could experience sudden power loss (overheating battery, motor, inverter, etc). In practice I haven't seen this yet even driving 80 mph for most of a day. The engine was able to cover slack from battery in my hill climb case. Did a few edits to add some additional info.
I think there is a misunderstanding to my concern. If the motor is spinning at 6,000 rpm @ 65mph because it is direct drive transmission that would lead to wear above a traditional CVT which would hold the RPM’s down. Honda is tracking our driving for a reason, the modes allow us to be test subjects. I’m just making sure I get the maximum life from my vehicle. I drive 36k miles a year and plan on putting on 150k miles. I’m technically inclined, but finding detailed info on this car difficult so far.
Being an overdrive gear the gas engine is at fairly low RPM when it is engaged at speed. Again, nothing you can do to control this. The only time the gas engine rpm is up near 6000 rpm can be at any speed in the eCVT mode when loads are high. I don't notice high RPM in the overdrive gear. My only comment is high elevation and mountain driving the engine runs at high RPM a lot more often. In Iowa it very rarely runs at high RPM. Electric motor RPM is no concern. Electric motors can run at high RPM all day. Heat is the larger concern to them. I will see if I can get a specific gas engine RPM when the clutch is engaged at a couple different speeds. Electric motor RPM will be max at 100 mph, so no worries from it at lower speeds. Again, the transmission is designed to be operated anywhere under 100 mph, the top speed limit is to prevent issues like you suggest. Being a Honda I suspect it will easily go 250k miles, but newer design so hard to say. One thing I have never had issue with was Honda engines even the high revving ones.
To add to this again, based on tire size, and specs at Honda if the final drive is 3.42 and overdrive/direct gear is 0.805 the engine RPM would be 2800 at 80 mph. This is why that mode is so efficient and only used at low loads and higher sAgain, in eCVT mode it is load based, but generally not high RPM. I am not ruling out design issues of course, it is possible they have some, but from a user perspective I don't notice an issue of them operating the transmission in a risky way around 80 mph. Being an eCVT with direct overdrive it seems far simpler than a traditional transmission and the "CVT" part is electronic, not a mechanical belt that will slip. Sure, a motor or engine could fail, but it would be a design issue or likely a manufacturing defect that we don't have control over. The car will reach 100 mph with gusto. That limit is the protection needed for the motors/engine. My guess is it has plenty of margin built in. If ratios are correct the gas engine would only be at 3500 RPM if mechanically driving the wheels. Traction motor is likely at RPM limit here.
Experimentally verified, torque pro on Android. Rough measurements from gas engine. With gear icon locked (clutch engaged, engine driving wheels mechanically) 2200 RPM at 60 mph 2900 RPM at 80 mph This gives a drive ratio of about 2.85 if tires are 766 revs per mile. Assuming that the specified drive ratio of 2.75 is correct (3.42 * 0.805), the discrepancy is probably tire wear and deflection and measurement error. Measurements were only 4% off or so, to me this is confirming the spec correct. Traction motor RPM isn't reported without knowing OBDII PIDs, but if RPM max is at 100 mph, at 80 mph you are at 80% RPM max. No issue.
I’m not engaging the gas motor on my hill climbs on the freeway. I save my charge for it. If you turn HV mode off and keep the car in ECO mode, the gas engine does not turn on. This gives the car good power up the hill and keeps the engine off which eliminates the engine drone. I’m just making sure that I’m not doing something that will be bad for the car over time. Putting the full load on the electric motor and discharging the battery quickly because of the high RPM. Electric motors do spool high with no issue, but there are bearings that will wear under normal strain. I would love to to see blow up of the transmission assembly and its internals.
I don't think it will be bad for the car, although I will comment that during a hill climb the engine started for me due to heat build up in the battery. Presumably, blue bar suddenly shortened after about 4 to 5 minutes of extended 80 mph up a 5 or 6% grade and engine started. Length of blue bar represents how much power is available from the battery. Point is, car will protect itself. I was hoping to go all the way up the hill in EV (since EV doesn't lose power at elevation). Yes, motor bearings can fail, but if they fail in less than a boat load of miles it is probably a design flaw or defect/quality issue (like plastic bearing roller cage in Chevy Volts that failed due to improper installation). After 17,000 miles I just drive the car and don't fiddle with mode buttons unless I want sport or econ.
