My only issue 2022 Prius Prime , hesitating to order

No problem passing or merging when the car set in its power gear.

SM-T813 ?

 

Correct. Off the line it does throw you back when charged. It’s just unfortunate it doesn’t last past about 28mph ish. The take off power is like, immediate as any electric car though.

Where the Prime suffers is having 4 people in the vehicle and going up hills at certain speeds. Steeper the worse. You kinda have to floor it and that’s when it gets noisy when using the ICE.

 

Um.. what car, what power gear?

If this is referring to the Prime, it is "Power Mode" and not a gear but mapping of the accelerator pedal.

 

Which only changes gas pedal response, but doesn't change acceleration times.

 

aargh! Not another debate on this topic...

 

You must have something wrong with your car or the way that you are driving it. I spend a lot of time on the freeway and my normal monthly travel includes traveling over mountain ranges. The 6% grade at the infamous Grapevine north of LA does not slow down the car at all. Neither does the climb up US50 heading west out of Lake Tahoe. Nor the climb going into the Siskiyous in southern Oregon.

One of the features I like about the Toyota hybrids is this; I occasionally get stuck behind an 18 wheeler which is trying to pass another 18 wheeler when both are floored while doing 35 MPH up a 4 or 5 percent grade. As soon as the truck gets out of my way I can accelerate back up to 65 in the same 10 seconds or so that it would take on flat ground.

 

The information we have on that topic includes both the as-explained-by-the-manufacturer kind:



and the as-shown-in-real-life kind:

and they agree.

The existence of some people who might nevertheless want to "debate" it shouldn't be a reason to shy away from providing that information where some readers might not have it.

 

To answer your original question Dan - yes, it can safely pass when properly planned.

As for the rest of the thread, it seems like you might enjoy the more enthusiastic car. I love my little Prime, but having driven more exciting cars I’ve caught myself numerous times looking at faster options. I can’t wait to see Toyota’s Corolla that is based on the overseas GRMN Yaris. Manual, over 270 HP, hatchback….

 

We just drove around 800 miles today, speeds up to 80+ in spots, 49 mpg
That's high performance, actually.

 

Does that include having 3 adult passengers in your car when you car pool? And some equipment?

If you re-read my earlier post I was was referring to going up steep hills with 3 fully grown adults weighing 170-200lbs each, and sometimes around 100lbs of equipment. STEEP hills. I didn't say merging onto highways

I'm talking about stopping at a light or stop sign, then going up it. It's almost has to be floored.

Guys we are dealing with a 3,370lb vehicle here with a maximum of 121HP. Don't know why this would be hard to believe.

 

It's the flat torque curve that the Prius has that makes the difference. You are starting with more torque than many cars have at 3000 RPM.

But it sounds like you live in a hilly area where private drives and such don't adhere to the normal guidelines for inclines. There are many streets like that in San Francisco. I've not had a problem driving there.

Since the gas pedal is not connected to the engine and the engine speed is not related to the tire speed, the gas pedal is basically a way to suggest to the car that you want to go faster or slower. If the car needs more HP, it will indeed race the engine to get to the optimal RPM for power generation. That's what it is designed to do.

 

I know we like pointing out electric motors have high torque at zero rpm, but that is the motor's peak torque. great for starting from a stop, but it drops as the rpms increase, which is part of the reason the Prius' acceleration drops off after 30mph.

Zero to sixty times from reviewers are measured at a track type setting, and usually involve running the car hard. Possibly to the point of causing damage. It isn't how a car will be driven on the road.

My 2005 Prius was slower measured than the current model. The HHR and Sonic probably weren't much faster. Never felt unsafe merging with traffic. The only time I did feel unsafe getting on a highway was at a left side entrance that had a stop sign, and the freaking truck behind me kept creeping up, and blocking my view of the highway's left lane.

 

Not only that, but it seems that the cars at the track are measuring from a moving start. I'm not sure, but it's something about starting the clock when the car's moved a certain distance. That moves the value of that measurement even further away from real life.

 

There is no car that can accelerate fast on a steep-enough hill—not even a Ferrari.

Acceleration from a stop has nothing to do with horsepower. It is related to (1) torque (the higher the better), (2) tire radius (the smaller the better), and (3) vehicle weight (the less the better). Prius Prime excels in all these three variables: (1) It is rumored to have a 400 ft–lbf of torque, putting most cars to shame. (2) It has small wheels. (3) It is a light car.

The formula for hill acceleration is as follows:

( hill acceleration (in g's) ) = ( 3.281 × torque (ft–lbf) / vehicle weight (lb) / tire radius (ft) ) − ( hill grade (fractional, like 0.10 (for 10%), 0.15 (for 15%), etc.) )

3.281 is to convert meters to feet.

The Prius Prime tire radius is 1.01 ft.

 

The ideas look right, the formula might need some details checked. I'm not seeing a factor for the final drive ratio, and the meter-to-foot factor is a little unexplained when all of the other length units are feet already.

In Gen 3 and 4 (and Prime) there is also the need to know whether one is using an MG2 torque figure from before or after MG2's reduction gear.

 

Right, I forgot to convert ft in ft–lbf to m, which cancels the conversion factor for the tire radius.

Yes, the final-drive ratio as well as the gear ratio need to be included.

The corrected formula is:

( hill acceleration (in g's) ) =

( gear ratio × final-drive ratio × torque (ft–lbf) / vehicle weight (lb) / tire radius (ft) ) − ( hill grade (fractional, like 0.10 (for 10%), 0.15 (for 15%), etc.) )

Final-drive ratio for the Prius Prime is 4.11. The tire radius is 1.01 ft.

According to my formula, 400 ft–lbf of net torque for Prius Prime would give something like ~ 1.0–1.5 g on a flat road, depending on what the gear ratio is.

You can easily test the g-force using your smartphone's sensor by installing an app that plots it as a function of time. I don't want to WOT mine.

 

Steep hills I am referring to doesn't mean almost straight up Lol.. Just a hill that most people who are good bicycle riders and in shape, if they are a little too tired are likely to walk the bike up the hill instead of riding. You guys know what kind of hill I mean.

 

Sorry, but you are assuming a commonality of experience that does not exist. I've seen bicycles climbing very steep roads at a slow walking pace. I've been known to walk a bike up a 1% grade and rested along the way. Other than that, I have no idea what incline you are talking about.

Can you post the names of the streets at the intersection that has one of these inclines that you hit so often while commuting? Google Maps is quite helpful in some of these cases.

 

The "net torque" in a Prius is kind of an accounting challenge. Part of it comes from MG2, and some comes from the engine and MG1 acting in concert. In a Prime, MG1 is further able to act alone in some conditions.

The torque from MG2 has a simple path through its reduction gear, then through the final drive, to the wheels. That ratio (product of the reduction and final drive ratios) never changes.

The torque from the engine/MG1 has a path through the PSD, where the torque gets multiplied by whatever factor the speed is getting divided by at any given moment. So the final formula has a term with a fixed ratio, and a term with a variable one.

There are some years-old posts where Bob Wilson took a crack at it, but that was pre-Prime. (Maybe he's taken a crack at the Prime too.)

The engine's torque curve is curvy in the way engine torque curves are. The MG2 torque curve is a flat line at maximum torque until the speed where torque ✕ RPM equals MG2's maximum power, and then decreases as RPM goes beyond that point.

 

Bethlehem, Pa is probably the area they are close too. When I'm in that area, it is the type of declines I'll down shift on. Some streets are probably close to San Francisco's. I'm a little south, outside of the mountains. Rte 309 south of there has some steep inclines.

The payload of a Prius is 825#, and the Prime with 4 seats is 670#.
Vehicle capacity weight | PriusChat
With passengers and luggage, those figures can easily be exceeded. The engine 's peak power output is at 5200 rpm. that is much higher than engine speeds a car with just a driver, on level roads, typically sees.