Ultra effecient combustion cars, under 1.5 litre, thoughts, pics, comments, designs, concepts Options

[pete-stevers]

i wonder what jake could do to a 1.7 to make it even more fuel effecient

[pbanders]

FWIW, my commute car is a 2009 Honda Fit Sport, with the paddle-shift AT. It replaced my '98 M3, which while enjoyable, was the most expensive car to maintain I've ever owned, used premium fuel, and got about 19 mpg on my commute. I replaced the skinny OEM tires with 205/50's, which helped handling and braking. It's a really fun car, I can drive it flat-out with barely anyone noticing, and still get 30 mpg on my commute. On flat highway drives it gets 40+ mpg. Extremely practical, gobs of front and rear seating room, fold-flat rear seats for a huge cargo area. Full of safety features, too. 5-star crash ratings, airbags galore, seatbelt tighteners, and active front headrests. It's also reasonably cute looking and fun to drive. 100K miles before the first tune-up, too.

[RoninEclipse2G]

There is a lot to be said for the guys that are dropping newer engines into older chassis. I've seen reports from a few of the guys that dropped Suby STi engines into 914's that were getting mid 30's for their highway MPGs. Normally that engine would only get mid to low 20's for highway mileage in the much heavier STi and that's a 2.5L engine.

[pete-stevers]

How about the VW Polo, 1.3 G40?
that would be a nice hot hatch!!

[Dave_Darling]

Lean burn is no longer in favor because it produces more NOx than current standards allow.

Diesels are vastly popular in most of Europe in large part due to the fuel taxes; diesel fuel is taxed much less heavily than gasoline. In the UK, where the two are taxed a closer amount, gasoline cars are still more popular.

Small lightweight low-powered aerodynamic cars are the most efficient, in general. Ever been in a Geo Metro? Think about using one every day on your commute. And think about the late-chugging makeup-applying screaming-at-children soccer mom in her Expedition. (Or, conversely, the breakfast-eating still-shaving newspaper-reading man in his F150 King Kong Cab pickup.)

I really like my CRX, and it gets by far the most use out of any of the cars we have in my household. But it's definitely not for everyone...

Google "ford probe iv" to see a very aero-slick concept car that got good fuel economy. Wander over to http://www.aerocivic.com for a look at a serious home-brew aerodynamic Civic which is ugly as hell but quite functional. It would be interesting to see what could be done in that vein by someone who wasn't trying to do it as cheap as humanly possible... If we could lose the currently-standard ideas of what makes a car good-looking, we could have cars that got significantly better freeway mileage. But I still couldn't drive the Aero Civic on a daily basis.

Sandy's Sprite (pictured above) should be a hoot to drive, and get at least half-decent mileage. The aero won't be great, but a nice modern modestly-powered engine and light weight should help it get decent numbers.

...Oh, gearing! Can't forget gearing! For cruising steady-state you want the absolute tallest possible gearing you can get. (You can go too far with it, but you are unlikely to with any reasonably-available OEM gears.) One reason the current Vettes get 30 MPG on the freeway is because they can cruise at 60 MPH at something like 1500 RPM. If you had a smaller engine with the same gearing, you would have to use more throttle to maintain that but you'd get even better economy.

More research you can do: Google "throttle pumping loss" and "BFSC map" to get an idea of how efficient different throttle openings are. (Hint: About 75% open is generally better than almost closed.) For tons and tons of ideas, see http://www.ecomodder.com and look for the "master list of modifications" that save gas. Most of them are things we wouldn't choose to do for various reasons (aesthetics, convenience, etc.) but some of them are quite easy and not that obvious.

--DD

[messix]

my get to work beater is a '95 geo metro, i drive like i stole it and get 39mpg back and forth to work 9 miles one way. i took it on a roas trip over the mountains and got 48 mpg. it has over 116k miles and is definately built like a disposable car, but it was cheap to buy, has saved me a shit load in money for gas when i had to drive my daughter 240 miles a week to school, and it seems to be the magical parking spot finder for going to big events where parking is scarce [some one always leaves 14' between cars that i can tuck it in to].

now if i could find some thing that rode quieter and better and still got 30- 40 mpg i'd be all over it. but nothing like that is cheap enough to buy.

[messix]

talk about old cars new engines... i'd love to do a '64-66' mustang with a modern 2L fuel injected 4 cyl with a 5 speed tranny. they got high teens mid twenty's with the old 190 cid inline six adn a 3 speed manual!

[patssle]

My college car was a 1996 Chevy Beretta. A decent sized car that got 37 mpg. Granted it was only 120 hp or so with a manual transmission...but it wasn't a shitbox shoebox sized car. And it was a little more stylish than most cheap cars (ignoring the Corsica style front).

They can make decent sized cheap cars that get good gas mileage and don't look like crap. They just don't want to.

[RoninEclipse2G]

DD, that article on the AeroCivic got me thinking about how so often designers and engineers don't really take the drag coefficient into account. My 95 Eclipse has an unusually low CD which helps it get ~40 mpg highway with a heavy 2.0 NA engine. I know a couple of guys that have gone to the crazy lengths of putting a complete underpanel on theirs and have seen a few extra MPG's on the highway. It's something I've seriously looked at for my own vechicle

[Gigamight]

My favorite gas-sipper was my 92 Honda Civic VX. It has no sound deadening, no carpet padding, hardly any seat padding... basically it was factory weight reduction to the extreme. Thing could SCOOT though. Plus I got almost 50mpg. Wish I still had that thing, they are going for a pretty penny these days.

[Todd Enlund]

I think that a TDI 914 would be cool, and should be capable of 60 MPG.

I also would love to build an Opel GT with a Toyota DOHC engine.

[Dr Evil]

Someday I WILL do a respectable TDI into 914 conversion.

[veltror]

Diesels are vastly popular in most of Europe in large part due to the fuel taxes; diesel fuel is taxed much less heavily than gasoline. In the UK, where the two are taxed a closer amount, gasoline cars are still more popular.


--DD

Statistics etc, (IMG:style_emoticons/default/poke.gif) Diesel is taxed HIGHER then petrol but the overall % of Diesel cars is higher then you may think, coupled with the fact that resale prices are better of a diesel.

In 2008 44% of all cars sold in the UK were Diesel and in 2009 42%. If you then look into the breakdown across segments the results are even more eye-opening.

Upper medium class 3-series, Audi A4 etc Diesel sales are 70.6%
Executive class 5-series Audi A6 Diesel sales are 77.8%
Luxury class S-class, Audi A8 etc Diesel sales are 54%
MPV class 59%
4x4 SUV class 82.6%


Since it makes little sense to have a small diesel car since by nature thay are runabouts etc Diesel is the way to go. As far as comments about accidents of small cars vs large cars it is not as cut and dried as people make out. It is all in the design and engineering, many large Chineese cars have abysmal accident results, in this case size does not matter.

If ppl want to drive huge cars etc which have crap economy then fine, their choice, however I object to the eco-Nazis telling me that electric is the answer it is not.
(IMG:style_emoticons/default/stirthepot.gif)
The Toyota Pious (not a spelling error) is outdriven, out handled, out economised by a VW Polo Bluemotion, and that is before you have to factor in the cost of disposing of the batteries.

So what do I drive? A Passat 170 TDI, the other half a petrol Tiguan 1.4TSI.
If I had the space i would have and drive a 1958 Plymouth Fury or a huge finned Caddy from 1959.

R

[zymurgist]

I could get 37 mpg in my RSX if I drove slower. I have a co-worker who has the exact same car, and she reports that she gets 37 mpg if she keeps it at 65 mph or below.

Not gonna happen. (IMG:style_emoticons/default/driving.gif)

[johannes]

Most Europeans also only own 1 car.

That was true in 1950 ...

[johannes]

This is the concept of the future. http://www.loremo.com/englisch/index.htm
They expect to sell cars next year...
four seats. It will be available with Diesel or Electric engine.

https://www.youtube.com/watch?v=uqkl1Ve_T8c


This one is also a great concept ... but only two seats and only electric
http://www.aptera.com/

https://www.youtube.com/watch?v=r_JV6QUIu5s

[zymurgist]

One of my friends (who drives an RSX Type S) goes nuts for the Aptera. He wants one in the worst way.

[EdwardBlume]

Lean burn is no longer in favor because it produces more NOx than current standards allow.

Diesels are vastly popular in most of Europe in large part due to the fuel taxes; diesel fuel is taxed much less heavily than gasoline. In the UK, where the two are taxed a closer amount, gasoline cars are still more popular.

Small lightweight low-powered aerodynamic cars are the most efficient, in general. Ever been in a Geo Metro? Think about using one every day on your commute. And think about the late-chugging makeup-applying screaming-at-children soccer mom in her Expedition. (Or, conversely, the breakfast-eating still-shaving newspaper-reading man in his F150 King Kong Cab pickup.)

I really like my CRX, and it gets by far the most use out of any of the cars we have in my household. But it's definitely not for everyone...

Google "ford probe iv" to see a very aero-slick concept car that got good fuel economy. Wander over to http://www.aerocivic.com for a look at a serious home-brew aerodynamic Civic which is ugly as hell but quite functional. It would be interesting to see what could be done in that vein by someone who wasn't trying to do it as cheap as humanly possible... If we could lose the currently-standard ideas of what makes a car good-looking, we could have cars that got significantly better freeway mileage. But I still couldn't drive the Aero Civic on a daily basis.

Sandy's Sprite (pictured above) should be a hoot to drive, and get at least half-decent mileage. The aero won't be great, but a nice modern modestly-powered engine and light weight should help it get decent numbers.

...Oh, gearing! Can't forget gearing! For cruising steady-state you want the absolute tallest possible gearing you can get. (You can go too far with it, but you are unlikely to with any reasonably-available OEM gears.) One reason the current Vettes get 30 MPG on the freeway is because they can cruise at 60 MPH at something like 1500 RPM. If you had a smaller engine with the same gearing, you would have to use more throttle to maintain that but you'd get even better economy.

More research you can do: Google "throttle pumping loss" and "BFSC map" to get an idea of how efficient different throttle openings are. (Hint: About 75% open is generally better than almost closed.) For tons and tons of ideas, see http://www.ecomodder.com and look for the "master list of modifications" that save gas. Most of them are things we wouldn't choose to do for various reasons (aesthetics, convenience, etc.) but some of them are quite easy and not that obvious.

--DD

Nice thesis there Dave.... thanks.

With the open throttle, I swear I got the best mileage out of my 993 in 6th doing 90-110 for long lengths of time... ie 280 between Cupertino and SF. I'm sure the lack of drag helped too...

[johannes]

Diesels are vastly popular in most of Europe in large part due to the fuel taxes; diesel fuel is taxed much less heavily than gasoline

That's true but Diesel is also more efficient. A diesel car will have 20% to 30% better mpg. If gasoline and diesel are taxed the same, the only reason people buy more gas cars is beacause they are cheaper.

[Brett W]

http://www.americanthinker.com/2010/02/con...fe_stand_1.html