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Hybrid vs Diesel

You know ... I'm still trying to figure out why there's so much PR (hype?) about the hybrids.

So you get a small car with avg 35mpg city/highway. Sure - city mpg is higher; but how many people want to buy another car just to drive in the city?

Take a look:

https://www.fueleconomy.gov/feg/hybrid_sbs.shtml

LOTS of cars avg 35mpg these days - and without the hybrid engine at all. My 1990 and 2000 Mazda Protege's have all been getting 35mpg in winter, and 38-40 in summer. So where's the advantage to a hybrid?

I've even heard from reliable sources (!) that a Corvette gets over 30mpg in highway driving. :smile:

Tom
 
I have had excellent experiences with diesels and do hope they come back.

That said I agree with Tom. In 1996 we purchased a new SW2 Saturn wagon. I had a trailer hitch installed and we loaded up our trailer and left on vacation to Missouri and Arkansas touring and trout fishing. We did not try to drive conservatively and even "tested" the acceleration in several instances. We averaged 35mph on the trip. Still have the car, it has about 120k miles, and it still gets in the mid 30's for mileage. It is also paid for. I have trouble figuring how a hybrid would save me money.

As for our TR6, we really enjoy stepping on the gas while we pass those hybrids. With a big smile on our faces!
 
NutmegCT said:
....

I've even heard from reliable sources (!) that a Corvette gets over 30mpg in highway driving.....

I have a friend who claims (I consider him trustworthy) to get well over 30 mpg on the highway in his Corvette. The thing even has a boatload of Lingenfelter mods - supercharger etc.

That said, I rode in a friend's hybrid SUV recently and was really impressed by the performance around town. I don't know what it was [I guess I wasn't <span style="font-style: italic">that</span> impressed...] but he said it had a Camry engine and it was pretty big.

Here in cold weather country I imagine that using the heater must keep a hybrid's engine running, no?
 
coldplugs said:
[
Here in cold weather country I imagine that using the heater must keep a hybrid's engine running, no?


Ya know i was wondering the other day how folks in the prius keep warm when they are running on batteries?..


mark
 
I've long held that the best "hybrid" would be a diesel electric. Small, sub one liter, diesel running at a steady rpm generating the electricy for electric motors at each wheel. The concept works exceptionally well for moving trains. HAve read some rumors lately that VW, for one, is working on just such a car.
 
swift6 said:
I've long held that the best "hybrid" would be a diesel electric. Small, sub one liter, diesel running at a steady rpm generating the electricy for electric motors at each wheel. The concept works exceptionally well for moving trains. HAve read some rumors lately that VW, for one, is working on just such a car.

It is a proven concept Shawn, but to compare it to a 1600+ hp locomotive engine/alternator is stretching it a bit. The horse power of the engine,<span style="font-weight: bold"> without using storage batteries</span>, must be the same as in a conventional drive, or very close to it. With storage batteries, a small engine/alternator concept works and charging can be done on the run to some extent, but a down time for full charging falls into play during the process. To get deeper into it, your getting into the Perpetual motion theory. Too many years have gone by and I forgot the mathematical formula for it, but that's why batteries, at the present time, are needed. Something to do with compression and friction on an object in motion, must have = horsepower to maintain such in a no wind condition etc, etc. Oh well, it's been to long.
 
tomshobby said:
I have had excellent experiences with diesels and do hope they come back.

That said I agree with Tom. In 1996 we purchased a new SW2 Saturn wagon. I had a trailer hitch installed and we loaded up our trailer and left on vacation to Missouri and Arkansas touring and trout fishing. We did not try to drive conservatively and even "tested" the acceleration in several instances. We averaged 35mph on the trip. Still have the car, it has about 120k miles, and it still gets in the mid 30's for mileage. It is also paid for. I have trouble figuring how a hybrid would save me money.

As for our TR6, we really enjoy stepping on the gas while we pass those hybrids. With a big smile on our faces!

Gotta love the older Saturns. I had a '97 SL2 with a stick shift that regularly got 38 MPG on the highway. Even at 128,000 miles it still ran like a champ.
 
sparkydave said:
Gotta love the older Saturns. I had a '97 SL2 with a stick shift that regularly got 38 MPG on the highway. Even at 128,000 miles it still ran like a champ.

You're describing my Protege's!
 
SilentUnicorn said:
coldplugs said:
[
Here in cold weather country I imagine that using the heater must keep a hybrid's engine running, no?


Ya know i was wondering the other day how folks in the prius keep warm when they are running on batteries?..


mark
The gas engine will run more in the winter on a Toyota hybrid. It will start and run until it hits a certian temp, then shut off until either temp, or electric supply command it back on. But, the newer Toyotas also use cemic heaters that run on electricity to augment the traditional coolant heat.
FWIW, the EPA test numbers that Toyota is required to display on thier hybrids for MPG are not really correct. In the region around here, with the hills we have, Prius owners typically get around 45 MPG in the summer, 38-40 in the winter
Still, an old Rabbit Diesel got better than that.
More to the point is that the official corprate goal of the Prius hybrid was extremely low emissions. It was never fuel economy. that is just a byproduct of the efficiency of the system, and that's what people saw.
The Highlander hybrid was an excercise in hybrid performance. It was a vehicle with extremely low emissions, decent mileage, and hot-rod V8 performance. The Highlander hybrid was the fastest vehicle in Toyotas lineup when it was introduced. (knowing the secret of "check mode" disables the traction control, and allows for some really impressive AWD burnouts!! trust me!)
the second generation Priuses are no dogs either. People just drive them that way.
 
Last year we were in England for 10 days or so (went to Lotus 60th anniversary bah while there) and rented a Ford Focus turbo-diesel. 50mpg average without trying for economy at all. I'm impressed!
 
Banjo said:
SilentUnicorn said:
coldplugs said:
[
Here in cold weather country I imagine that using the heater must keep a hybrid's engine running, no?


Ya know i was wondering the other day how folks in the prius keep warm when they are running on batteries?..


mark
The gas engine will run more in the winter on a Toyota hybrid. It will start and run until it hits a certian temp, then shut off until either temp, or electric supply command it back on. But, the newer Toyotas also use cemic heaters that run on electricity to augment the traditional coolant heat.
Sorry to dig up an old thread but I saw this and thought I could add something.

I've had a Prius for 3+ years now. In the winter the engine takes more time to get up to temperature, and the engine will run continuously to that point if the heater is turned on. (If not there is a much lower intermediate temperature where the car's hybrid system kicks in earlier.) This does effect gas mileage a lot because it's so high to begin with (but only for the first 5-10 minutes, so for extended driving the difference is negligable).

Once it's up to temperature the Prius has what is basically a big thermos bottle that is filled with hot coolent every time the engine shuts down (in motion or when shutting the car off). The heater draws heat from that bottle. Long before that bottle cools the engine cools to where it needs to kick back on anyway.

In practice there is no interruption of heat under any circumstance.
 
Dave - thanks for the info. Never knew of the "heat storage" in a Prius before. And your comment that using the heater "does affect gas mileage a lot" is really interesting.

Say, what mpg are you getting? What kind of driving (city, interstate, hills, etc.)?

Thanks.
Tom
 
Mileage varies widely in a hybrid based on circumstances and driving styles. When you buy one you don't buy high gas mileage any more than you buy consistent low 0-60 times when buying a Viper. Instead you by the <span style="font-style: italic">potential</span> for high gas mileage.

In the warm months of the year I get between 45 and 48 mpg city (w/o a/c) with every tank, using the car as a family driver (<span style="font-style: italic">something most people couldn't do in a sub-compact or compact car, myself included</span>) with no special techniques or mods. Using the a/c drops that down by 3-5 mpg depending on average trip length.

You can get much better than that by over inflating the tires (<span style="font-style: italic">even a little helps a lot--40 psi is not unusual and 44 psi is reccommended by many drivers on priuschat.com, you don't have to go to hypermiler extremes</span>), and by driving with an accelerate-&-coast driving style. However I don't do that and wouldn't recommend it.

In the winter my mileage drops to between 39 and 42 mpg typically, mostly because 90-95% of my trips are 5 miles or less and the car rarely is up to temperature for most of the driving. Super cold snaps (<span style="font-style: italic">20 degrees F or less for many days at a time</span>) can drop it even further. My worst tank ever has been 34 mpg.

My highway mileage has varied between 44 and 51 mpg, depending mostly on wind direction and load.

There are a number of people who view this as a challenge, and on priuschat.com I believe the current record is 57 mpg over 100,000 miles for unmodified cars in daily use. The record for one tank in an unmodified car is 116 mpg, which was set driving back and forth over a weekend in August (<span style="font-style: italic">multiple drivers taking turns</span>) on a very busy 4 lane road in suburban Pittsburgh. It took more than 1.5 days to burn one 11 gal tank of gas!
 
DaveatMoon said:
The record for one tank in an unmodified car is 116 mpg, which was set driving back and forth over a weekend in August (<span style="font-style: italic">multiple drivers taking turns</span>) on a very busy 4 lane road in suburban Pittsburgh. It took more than 1.5 days to burn one 11 gal tank of gas!

I think that this is one of the key points: Hybrids are MUCH more efficient when they are in stop and go traffic, when their electric motor is moving the car, and the braking is charging the batteries. Many people talk about highway mpg, and the prius gets good highway mileage, but if you were to compare the prius to the saturn that everyone keeps talking about, the city mpg would be FAR better in the prius.

Which is why I loved my Diesel Jetta. Up to 50 mpg on the highway, but never worse than 44, no matter how bad I drove in the city. That is, at least until the garbage truck hit it three times.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Many people talk about highway mpg, and the prius gets good highway mileage, but if you were to compare the prius to the saturn that everyone keeps talking about, the city mpg would be FAR better in the prius.[/QUOTE]
I had a 1997 Saturn SL2 from 1997 until 2001. It was a great car. With an automatic, I got a consistent 32/38 mpg (city/hwy) the entire time I owned it. When my 2 kids got older I <span style="text-decoration: underline">had</span> (but didn't want to) get rid of it for 2 reasons:

Interior volume: 1997 Saturn - 77 cubic feet; 2005 Prius - 96 cubic feet.

Cargo volume: 1997 Saturn - 11 cubic feet; 2005 Prius - 16 cubic feet.

(see www.fueleconomy.gov side by side comparisons)

There has yet to be a subcompact hybrid car marketed anywhere to my knowledge. I (for one) cannot wait to see that happen! :cooler:
 
DaveatMoon said:
Once it's up to temperature the Prius has what is basically a big thermos bottle that is filled with hot coolent every time the engine shuts down (in motion or when shutting the car off). The heater draws heat from that bottle. Long before that bottle cools the engine cools to where it needs to kick back on anyway.

In practice there is no interruption of heat under any circumstance.

Actually the thermos bottle is part of the emissions system. As a nice side benefit, it helps out with heating.

A gas engine needs to be up to temperature in order for it to work efficiently and cleanly. Since the prius keeps shutting the engine down, it would be at less than optimal temp a large part of the time which would cause very high emissions. The thermos ensures that as soon as the engine kicks after the initial warm up, it returns to normal temp almost instantly.
 
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