"Extra Mild" Hybrid?

The Prius engine also has a crankshaft that's offset from the cylinder.

Toyota gets all "techy" on us, explains Atkinson cycle

 

My BMW 328d has the regenerative brakes, coupled with an AGM battery, and start - stop. It took a few days to get used to the start - stop but now I don't even notice it.

 

The reality is that a true "hybrid" is a fuel-powered generator and electric motor (with maybe an extra battery or battery pack for voltage stability). This is what modern locomotives are, and you can take MOST ANY vehicle and do this to get better gas mileage than a straight-forward ICE because you only run the ICE to generate the needed power, not to overcome inertia or accelerate the vehicle.

The Prius uses a specially designed hybrid drive which is an amalgamation of technologies to (as I theorize) produce a fuel/electric drive system in the smallest/least amount of size/weight they could achieve. For something the size of the Prius (or smaller) a standard ICE/electric motor "hybrid" would be larger, heavier and cost fuel economy because any electric motor capable of running 100% electric at highway speeds (with respectable acceleration) would have to be much more robust than what you find in Toyota's Synergy system.

Likewise, this is why Toyota's other "hybrid" platforms are so lackluster when MPG is concerned. You can't just put the Synergy system into another platform and expect the same results as you get in the Prius. The Tundra would get negligible benefits as compared to a proper electric motor/generator hybrid because the Synergy drive is underpowered for the platform...using more gas on the ICE side...just as going uphill all the time in a Prius will average you 25 mpg instead of 50+ mpg. Compare the Camry or Highlander hybrids to their ICE counterparts. The improvement in mpg just isn't that impressive.

 

I suspect you consider them 'lackluster' because you are looking at MPG, not the percentage change in MPG, or the amount of gas saved annually.

 

The understanding I have is that unless your vehicle will sit idle for more than X time, shutting down the motor WILL NOT save gas or reduce emissions. Never mind that an ICE vehicle loses most everything powered (steering, brakes, A/C) when the engine is not running). There is also the issue with the starter. I'm not sure how the Prius does it, but I suspect the Prius has a much more robust starter because of how often it is used. You'd have to put a very-heavy duty starter on an standard ICE if it shut down when you came to a stop because it would be cranking the engine every time you want to start again.

They'd do better to jigger the ECM of an ICE to really lean out the idle when the vehicle stops so it's using the absolute least amount of fuel needed to keep the engine cranking.

 

Maybe I'm not following you, but I don't see how the others would really impress. Statistics are easy to manipulate to give false impressions. Double the mileage on a 10 mpg vehicle is impressive if you are forced to stay with that platform but 20 mpg is not impressive by itself.

Part of owning a pickup truck or SUV is the higher gas cost because it's designed for hauling which requires more energy. Paying an extra $2,000-$3,000 to get slightly better MPG makes less sense...especially if performance suffers and/or you have higher maintenance cost issues that go with it.

I would NEVER have considered the Prius before Gen 3. It cost more, is nigh impossible to repair yourself (too technical for most DIYers), and has new stuff that is expensive to replace WHEN (not IF) it fails. I needed time to see that the Prius was well-made and really wasn't a big repair bill waiting to happen before I felt comfortable paying extra for the hybrid technology.

For 50+ mpg, the cost and risk is worth it. To get 5-8 mpg (at best) over what I currently get, it don't think it's worth it.

 

The Prius has no dedicated starter motor. Motor/Generator 1 is a 15 kW AC device that acts as the starter motor and frequently as the Alternator. Under some heretical conditions it also helps propel the car.

You are correct, just because you would save way more gas and money, does not mean it would be impressive.

I went from a 24 MPG Subaru Forester to a 46 MPG Gen 2 Prius driving each 30,000 miles a year

30000/24 = 1250 gallons
30000/46 = 652 gallons

so I saved 598 gallons of gas each year.

Had I moved from a 10 MPG pickup to a 20 MPG pickup driving the same 30,000 miles each year

30000/10 = 3000
30000/20 = 1500

I would have saved 1500 gallons of gas each year, 902 gallons MORE than I did save. (about $3500 more)

But if you do not do the math, it does not look 'impressive', so GM had trouble selling their Hybrid pickups and SUVs

"they offer excellent EPA mileage ratings of 20 mpg city, 23 highway—for a best-in-class 21 mpg Combined"