A Prius type hybrid's performance on a mid-size or a XUV

Question

I don't know a lot about car engines and I know less about electric engines. I've heard the Prius type of hybrid will likely be the future for all cars. However, I wonder if that tiny 1.3 litre engine has enough guts for a mid-size or large-size automobile or a crossover XUV to punch it in order to merge onto the freeway?

I'd like to hear a mechanic's take on the Prius type of hybrid as to acceleration for the larger vehicles, 0 to 60mph, for merging on the freeway. I’d also like to know a mechanic’s opinion whether or not the gasoline engine can take the wear of a lot of long distance highway driving say over five years.

Lastly does the gasoline engine turn a generator or an alternator to make electricity for electric engine on the drive train. The advertising diagram says generation, but I believe the electric engine uses alternating current.

Answer 1

They've been on the market for years, you just didn't notice.

Toyota's largest hybrid powertrain is found in the Lexus LS600h car and RX  SUV.  It's just like a Prius, but scaled up quite a lot.  The gasoline engine in these has plenty of power for anything.

The prius drivetrain has the engine and the electric motor both connected to the transmission through a set of gears that acts as a differential.  Either one or both can drive the car.  The engine can drive the car and turn the motor as a generator at the same time. The motor can drive the car when the engine is off.

Answer 2

To answer your question on the Prius reliability and performance, here are the facts:

- The Prius has a 0-60 acceleration time of 10.4 seconds.  That's like any sensible 4-cylinder family sedan.  No problems merging into highway traffic.   Prius drive system has a combined 110hp from the gasoline and electric motors.

- The transmission in the Prius is a VERY simple system--  One single gearset with just 22 moving parts, no torque converter, no clutch, no belts, no gear-shifting wear and tear.  Its simplicity is why it's much more reliable than regular multispeed transmissions with 100+ moving parts.  Info on how the Power Split Device transmission in the Prius works:  http://eahart.com/prius/psd/

- The Prius has the capability to shut off its 1.5L atkinson-cycle gasoline engine when it is not needed, such as when the car is stopped or at low speeds when running on electric alone.  For that reason, the Prius gasoline engine actually experiences LESS wear and tear than normal car engines.  The engine can last as long as it is maintained properly (oil and filter change every 5000 miles and other scheduled maintenance).

- The Hybrid Synergy Drive in the Prius has two 3-phase AC induction motor/generators, and it converts the power between AC and DC via a solid-state inverter system for storage or draw from the battery.  Prius has no alternator because the MGs can work as motors or generators depending on need.

- Toyota's warranty on the Hybrid Synergy Drive system is 8 years / 100,000-miles, or 10 years / 150,000-miles in the 8 states with California-standard emissions regulations.

Reliability of the Prius is not an issue.  Vancouver has been using the Prius as taxi cabs for years, and many have racked up 200,000 miles (way beyond warranty) with no problems whatsoever:  http://autos.canada.com/green/story.html...

Answer 3

It doesn't take very much power to keep a vehicle going at a decent clip down the road.  My guess on my truck is I need only about 15hp, probably less, to hold 60mph.

All the rest of that power is for getting up to speed at the kind of acceleration Americans demand.  But with an electric motor assist, you've got the electric to provide big torque at low speeds and provide plenty of thrust, and then the little gas engine for steady-state cruising.  Even a big truck like an Excursion could be well served by a 60hp engine if it just had a big electric motor to get off the line.

In a full hybrid the gas engine can drive just the wheels, just the generator, both or neither as the situation demands.  That makes for a pretty complex transmission, but Toyota seems to have figured it out.

As to the question of the little engine lasting five years, of course.  There are 2nd-gen Prii out there that are five years old right now, racking up the miles.  There are also 1st-gen Prii, and a great many older vehicles with even smaller engines (Geo Metro 1L 3-cyl) that are still hanging tough.