CVT Transmission Question

probably the gas engine firing up. no worries.

 

If your holding the brake down very hard you may be engaging the hill brake. I've noticed on my Prius that when I engage the hill brake I can feel it release when I take off. Hope this helps..
Happy Prius owner at 16 K miles..

 

Welcome to PC and congratulations on your new ride.

If you are engaging the Hill Brake you will see a yellow icon of a car in the left side of the instrument panel. You have to press the brake fairly hard to engage the hill brake.

The hill brake holds the brake for two seconds when you are on an incline to give you time to take your foot off of the brake and reach the accelerator without rolling backwards.

 

I've found our 2010 transmission very smooth (8 mo's, 12000 km). I haven't noticed any jerks or stutter. The only thing I can detect is slight "gear" feel, if rolling in the garage in EV mode, just a sense of feeling the individual cogs as it rolls, in very quiet, low speed conditions.

I would let your dealership test drive it, see what they think. Even if there is an issue, there's a possiblity they will turn a blind eye to it. OTOH, it could be normal. Either way, just make sure there's some record of your visit, just in case it worsens down the road.

FWIW, with our previous 06 civic hybrid, with a more conventional CVT transmission, there was sometimes a noticeable on/off lurch, often when rolling low speed corners and getting back on the gas. Never got worse, I thought it might be computer related, ie: the conditions were just on some edge, and it got the stutters.

 

As a point of reference, the Prius doesn't really have a CVT in the mechanical sense. The Prius has one set of fixed gears that always stay engaged and always stay at the same ratio. There is no standard clutch, torque converter, or belt cone drive.

Effective variable gearing is accomplished by an electrical drive path in parallel with the fixed mechanical path.

Because of this, any hesitation you might feel is from the engine starting, not some mechanical gremlin in the CVT.

Tom

 

It has an electric CVT (E-CVT). Just like an EV with a single speed transmission, Prius does away with single speed by mixing both electric and gas. Electric motor is used as low gear (high torque) and gas engine as high gear (low torque). The amount of mixing is variable and it is computer controlled.

A full hybrid has two powertrains with strengths and weaknesses that complement each other. The idea was to use them when they do best and get rid of the complex mechanical gearbox and the legacy components (starter, alternator, belts, etc..).

The gas engine (ICE) came on because the battery could not provide enough electricity (27kW max) to feed the traction motor (60kW). ICE turns the generator to create more electricity. ICE also add more torque (72%) to the wheels.

 

here is some info on how Prius HSD works, including animation of how 2 electric motors and ICE mixed: Toyota Prius - Power Split Device

 

yeah it is normal; it will get slightly better after break in.

 

Keep in mind, it is for Gen1 Prius. Gen2 MG1 goes up to 10,000 rpm. I think Gen3 MG1 goes up even higher.

 

Does anyone know of an update to this simulator to include the Gen II and Gen III rpm's ?