Do Hybrids Really Make Sense?

[oldtamiyaphile]

Originally Posted by IamIan

J

#C> Efficiency / Performance ICE vs Electric Motor.

If you can have the ICE run 100% of the time only at it's peak efficiency point it's no contest the ICE-Only wins ...

(1B)
Regenerative braking is 100% gain for the HEV .. a ICE-Only vehicle will throw 100% of that energy away.

In heavy stop and go traffic this adds up quickly to large amount of energy.

In other types of driving it adds up slower ... I've read the 'average' US commute burns up ~6% of the fuel energy to braking alone .. Link.

I P&G/ EOC at BSFC close to 90% of the time so I guess the ICE wins. The question was whether a hybrid does anything that an optimised ICE can't and the answer is really, not much.

Regen braking, my Fiat only runs the alternator on overrun/ braking so it does recapture lost energy (a lot of European cars have 'intelligent' alternators). How much? Well let's say I can drive at least 200km of country roads without the alt kicking in. Mazda's capacitor system lets it regen/ store even more energy.

Of course, the regen argument doesn't really apply to hypermilers who don't brake anyway. See thread: Coasting more efficient than regen - Audi

There was talk of VW releasing a manual ICE car with an auto EOC feature. Team this with a regen alternator and a driver who understands BSFC and you're on a winner.

PS we all know 1st gen Insights are efficient, but they're also small, alloy bodied, aerodynamic and cost new nearly three times as much as a 1.0 Suzuki (with four seats). That means they still haven't reached the break even point cost wise (and like early Prius models, they were likely sold at a loss). We also know that a aeromodded Suzuki/Metro can match an Insight in the right hands.

Suzuki Swift 1.0 cost in 2000 $14k (locally).
Gen 1 Insight cost $40K (locally).

Fuel cost (using a deliberately high local cost of $1.50/ litre (or $6.60/ gallon!), means the Insight needs to travel 577,000 trouble free km to break even with the Suzuki. So no Insight owner I'm aware of has a car that's actually reached the break even point yet! Now if you're paying around $1/gallon (so I hear), you'd need to travel nearly 4 million km to break even with the Suzuki - let alone if you hypermiled the Suzuki. Like I said, 1st Gen owners have a really skewed perspective on this issue.

[Hersbird]

Originally Posted by serialk11r

This is when quoting wikipedia is dangerous, and it helps to know how engines are actually designed and what regulations do what.

I'm not going to go into why a diesel doesn't need a throttle. Diesels are direct injection by definition and that has nothing to do with a throttle.

Ever wondered why diesel engines need NOx traps? Stratified injection would need an NOx trap as well because the cat would not be able to remove NOx with lean burn. No car in the USA has stratified direct injection, the only cars in this country that run throttleless are BMW N20, N52, N55, etc. engines, Nissan VQ37VHRs, and Fiats equipped with Multiair.

Lots of diesels are not direct injection and have a throttle body, this is also another place where it helps to know how engines are actually designed...
I'm just busting your chops, I'm not a jerk like some people on the internet.
Maybe you mean current US diesels and current US GDI motors. Maybe I didn't, either way, it's good to know we can communicate with each other respectfully.

[cRiPpLe_rOoStEr]

Originally Posted by Hersbird

Lots of diesels are not direct injection and have a throttle body, this is also another place where it helps to know how engines are actually designed...

Trying to make an IDI Diesel comply to current emission standards would be a PITA, but they're often pointed as less energy-intensive (thus cheaper) to manufacture. Another aspect to consider is their ability to run on vegetable oils, which may be the least energy-expensive among viable vehicle fuels and can be supplied from a wide range of feedstocks. Considering the energy-efficiency increase in the vehicle manufacturing and fuel supplies, it's already somehow advantageous over hybrids.

[jamesqf]

Originally Posted by IamIan

The HEV system replaces the ICE-Only need for both Alternator and Starter ..

A couple of minor corrections here. First, the Gen 1 Insight does have a starter, which will start the ICE if the IMA battery is very low, or the system is inoperative. However, the OEM 12 Volt Insight battery (which unfortunately is pretty well impossible to find) is much smaller than the group 51 used on similar Honda ICE cars, saving about ~15 lbs.

Second, the Insight's electric motor replaces the flywheel of a conventional ICE, and also serves as a dynamic balancer, saving more weight.

[Occasionally6]

Originally Posted by oldtamiyaphile

I P&G/ EOC at BSFC close to 90% of the time so I guess the ICE wins. The question was whether a hybrid does anything that an optimised ICE can't and the answer is really, not much.

Do you think you could do that - operate regularly any where near 90% BSFC - in a 500+ BHP Corvette (say)? Disregarding any value judgement about the need for that power, the further the peak power requirement is from the average the better the hybrid looks.

Xist asked about optimising a hybrid for highway use. Ignoring any acceleration to get up to speed, the optimum "hybrid" for that circumstance is probably no hybrid at all, with the average power being fairly constant the ICE could be right sized to suit.

[niky]

Originally Posted by cRiPpLe_rOoStEr

Trying to make an IDI Diesel comply to current emission standards would be a PITA, but they're often pointed as less energy-intensive (thus cheaper) to manufacture. Another aspect to consider is their ability to run on vegetable oils, which may be the least energy-expensive among viable vehicle fuels and can be supplied from a wide range of feedstocks. Considering the energy-efficiency increase in the vehicle manufacturing and fuel supplies, it's already somehow advantageous over hybrids.

Yeah... I can't recall any modern diesel that doesn't have direct injection.

I think it would be possible to run a veggie burner with direct injection... you simply have to have extra injectors for lubrication and for particulate filter regeneration.

[oldtamiyaphile]

Originally Posted by Occasionally6

Do you think you could do that - operate regularly any where near 90% BSFC - in a 500+ BHP Corvette (say)?

More power just shortens the 'pulse'. I plan on building an Aerial Atom style kit car and have wondered what it would be like to hypermile, it will just mean the ICE only pulses for probably a second or two at a time. Keep in mind you'll never get 500hp anyway in top gear at hypermiling speeds, BSFC might see you with 200hp, which is actually quite usable.

[redpoint5]

Doesn't Old Mech have a patent on a hydraulic hybrid? I'd really like to see an efficient way to store mechanical energy so that the engine could be pulsed while the vehicle speed remains constant.

Sure, pulse and glide takes much of the advantage away from hybrids, but how many people would tolerate their speed constantly fluctuating 10 mph or more? I certainly don't, and that's why a hybrid makes sense for me. Perhaps a non-electric hybrid would make even more sense. Converting mechanical energy into electrical, then into chemical, and then back into electrical and then back to mechanical is a silly process.

[cowmeat]

We also know that a aeromodded Suzuki/Metro can match an Insight in the right hands.

Ask Darin how much time, money and effort it took him to get the numbers he's pulling in his Metro. That's a labor of love he's got going on there, or you'd see twenty Metros/Swifts pulling that kind of mpg. I came within a couple miles a gallon of his average my first tank just driving my Insight, no mods necessary, and I carpool mine.

Suzuki Swift 1.0 cost in 2000 $14k (locally).
Gen 1 Insight cost $40K (locally).

That statement is pretty much irrelevant on this site. How many of us actually drive new cars here? I wonder what the average cost of a vehicle is on this site?

Like I said, 1st Gen owners have a really skewed perspective on this issue.

I bought my car for the exact purpose it was built for: to use as a two-person commuter car and to get the best gas mileage imaginable without sacrificing anything. I carpool it almost daily, drive it moderately, and without the first mod I get better gas mileage than almost anybody on this site (a site dedicated to raising your mpgs). I match traffic without slowing everybody down around me. It's 14 years old but looks almost new. It only has 112K miles on it, so I should conceivably be able to drive it another ten years.

If I hadn't done the research and weighed all my options, I would still be driving the Black Widow, getting ten less miles a gallon that hard way with no AC, forced to take back roads to P&G, etc . . . . . Not sure where you think my perspective as an Insight owner is skewed, the car perfectly matches my driving needs.

[serialk11r]

Originally Posted by Hersbird

Lots of diesels are not direct injection and have a throttle body, this is also another place where it helps to know how engines are actually designed...
I'm just busting your chops, I'm not a jerk like some people on the internet.
Maybe you mean current US diesels and current US GDI motors. Maybe I didn't, either way, it's good to know we can communicate with each other respectfully.

Sorry, I suppose you are correct about indirect injection existing.

But throttles on diesel engines were only used briefly to cope with emissions and modern engines don't have them.

Either way, spark ignition engines need valve trickery to control the air if you don't want to use a throttle to do so since they can't run ultra lean.