Spork Boards

Reciprocating Mass

rino's Avatar Picture rino – December 09, 2007 10:14AM Reply Quote
As started by Binky in land of old ...

A place to discuss your wheels!

"Use your wheels, that is what they are for." - Hawkwind

Cloudscout – May 23, 2008 11:18AM Reply Quote
Det finnes ikke dårlig vær, bare dårlige klær!
I can't speak to the ultimate efficacy of current hybrids (the true environmental cost of the battery systems has me skeptical) but the idea is sound.

People have grown accustomed to cars that respond quickly when they press the gas pedal. This expectation has led to engines grossly overpowered for typical uses. When you're cruising down the highway, you don't need an engine with that kind of power. Hybrids have weak engines in them and use the electric motors to compensate for the lack of acceleration. Sure, the greatest improvements in fuel efficiency come from frequent start/stop driving rather than highway use, but hopefully they'll continue to improve the hybrid concepts.

El Jeffe – May 23, 2008 11:19AM Reply Quote
What a journey.
Yeah, this prius is slow to accelerate, but I was already doing that with my normal cars to save some on fuel.

stan adams – May 23, 2008 11:42AM Reply Quote
The energy density of gasoline/diesel is hard to argue with -- biased, to be sure, but the math is mostly accurate: http://findarticles.com/p/articles/mi_m0CYH/is_19_6/ai_91964920

The shorter the trip and the less need for cargo, the less important that is, but you can't change physics.

I want my next vehicle to be a diesel, probably try and hold off purchasing until 2011. (sounds like f'ing sci-fiction meets Pre-War technology, no wonder steam punks are the "next next big think...)

tliet – May 23, 2008 07:01PM Reply Quote
Stan, I wasn't attacking the Prius; quite the opposite. I'm just genuinely wondering if a regular petrol/diesel engine car would reach the same mileage because not that many people have a trajectory that is perfect for hybrids.

I'd say conventional cars could easily be equipped with a cut off switch that would silence the engine while standing still and start it when the foot is taken off the brake.

Interesting link: petrol prices in the world: http://www.aaroadwatch.ie/eupetrolprices/default.asp.

Edited 1 time(s). Last edit at 05/23/2008 07:02PM by tliet.

stan adams – May 23, 2008 07:11PM Reply Quote
You're right -- back in the 80's VW equipped some test cars with things that would kill the motor went at idle and then instantly start the thing with either an integrated high torque clutched starter or a high velocity energy storing flywheel and the savings for "in-town" type operations were signficant BUT the catalytica converters would not stay hot so that the damned emmisions would never come down and that doomed them.

The fuel price data looks about right to me, and goes along with what I was saying about fuel prices as a function of wages -- for most people in the US employment pool is pretty goddamned the "bite" small...

El Jeffe – May 24, 2008 06:07AM Reply Quote
What a journey.
after driving this for a day, I'd say that a conventional engine's cut-off/restart SHOULD really be a hybrid anyway. It just feels like it should, because this feels like a smart way to do the cut-off-restart. A conventional engine would have some issues, I think. Plus, at stop lights, the engine does not always cut off. This car MAKES you acc/dec-elerate smoothly/slowly. You have to mash the pedal (WHICH I HAVE NOT DONE) to get much else out of it.

Today's journey will start putting money in my pocket. A trip out of town to visit family. It should save me $20-$25 just in gas. The kids will get their first test of whether or not they can sit and touch each other's arms/shoulders without spewing venom all over the place. I wonder what kind of incentive I should dangle in front of them to do so?

John Willoughby – May 24, 2008 03:39PM Reply Quote
Cyberdyne Systems Customer Support
>I wonder what kind of incentive I should dangle in front of them to do so?

Most unruly kid has to push the car home.

El Jeffe – May 24, 2008 04:46PM Reply Quote
What a journey.
Okay, I topped off the car last night. We took the short-ish trip today. On the way home I JUST HAD to go to the same pump and top off again to calculate mileage.

Now, it's not much distance so the accuracy needs to be high to get better results, but the first top-off I got 58.1 mpg. Air conditioner on the way back. Plus, 5 butts-in-seats, too.

I'll see how the over-time calculations come back. I was not the slowest on the road, but I could see them from 'here'. :)

rino – May 24, 2008 10:11PM Reply Quote
In America, the only respectable form of socialism is socialism for the rich.
That's all highway? I thought highway was less in one of those.

Anyway, my 161hp Mini Cooper S is averaging 34mpg over a period of several months. I raised it in the last month or so just by going easier on the pedal.

A heck of a lot of energy is wasted in the way people drive. Bunny starts and driving hard up to lights only to brake hard... it's crazy.

I just witnessed a near .20 cent increase in fuel costs in about 5 days. Filled up my Mini at this Exxon and it was 4.03 per gallon for premium, Friday filled up the Jeep with regular and IT was 4.03!!! Premium was 4.19.

I don't get why diesel is so damned expensive here versus regular petrol. It's about 4.70 now around here.
Of course the new diesel VW's coming over have an advertised 65MPG on the highway... that'd cut my fuel usage in 1/2 whereby I'd use only one gallon of petrol a day rather than the two I use today.

Even better is talk of train service up to the city where I work ... I'd be on that seriously.

Cloudscout – May 24, 2008 10:14PM Reply Quote
Det finnes ikke dårlig vær, bare dårlige klær!
I've been "kinder" to the gas pedal in my Murano lately and I'm getting 22.4 mpg. That's with a lot of city and rush-hour driving. When I'm kind to it during straight highway driving, I can get over 26 mpg.

tliet – May 25, 2008 03:53AM Reply Quote
Diesel has historically been much cheaper over here, but it went from like 1 euro a litre to 1.50 euro a litre within a year. Regular petrol hasn't gone up that bad.

I made a spreadsheet of all the receipts that I still had since the summer of '06 in the old Benz. In the last 7 months the average milage (over 2900 km/1800 miles) has been 8.55 km/l or 20.11 mpg.


Here's a chart with the average petrol price in my neighbourhood over the last 2.5 years:

I should cycle even more...

edit; changed to euro/gallons

Edited 1 time(s). Last edit at 05/25/2008 03:58AM by tliet.

El Jeffe – May 25, 2008 07:12AM Reply Quote
What a journey.
No, my first tank was not all highway. But probably 70%.

tliet – May 25, 2008 07:34AM Reply Quote
Really good figures Bill and it's what CS says; the way of driving can save you at least 15% right there.

El Jeffe – May 25, 2008 08:57AM Reply Quote
What a journey.
I might take an even longer trek today. Still deciding.

stan adams – May 25, 2008 01:58PM Reply Quote
Three big factors are driving diesel pricing--

#1 The refiners that have not made the switch to the low sulphur methods are now forced to do so.

#2 The older lower temperature cracking yield have been switched so that each barrel of crude now yeilds much less diesel

#3 Trucks and locomotives are going damned near 24x7 moving crap from China to all points in the US burning MUCH more diesel

At least the number 1 reason ought to be temporary...

El Jeffe – May 25, 2008 06:11PM Reply Quote
What a journey.
Today's trip of about the same mileage and mix, but into hilly areas, resulted in 51.6 MPG And again, some A/C. I probably don't know how to maximize my hills ups-and-downs anticipation and such.

Cloudscout – May 25, 2008 06:59PM Reply Quote
Det finnes ikke dårlig vær, bare dårlige klær!
Stan, I wouldn't count on #1 being temporary after reading this ArsTechnica story on BioDiesel or this StarTribune story on government BioDiesel mandates.

Unless diesel derived from algae makes some big leaps into mass-production, things are going to get a lot uglier before they get better (that is, IF they get better).

morganti – May 28, 2008 10:41AM Reply Quote
Here ya go bill. All sorts of info there, but the one that interested me was the whole "state of charge" thing. Basically, you draw down your battery going up a hill that you "know" (based on your route) you're going to go back down, and thus recharge it all the way down (by braking lightly and "collecting" the gravity energy). Also talks about "wind resistance" but that's like WAY beyond my DIYness.

I could however see a time when your GPS navigation system takes this info into account and actually "shuts down" the engine on the "uphill side" of your route, and "lightly brakes" on the downhill side.

Morg "Or something to that effect." anti

El Jeffe – May 28, 2008 11:08AM Reply Quote
What a journey.
The hypermiler pages I've read say they speed up going down hills so as to go up the next hill 'cheaper'. I just put my cruise on and get 50+ mpg so far. :)

El Jeffe – May 28, 2008 11:10AM Reply Quote
What a journey.
for those that missed the original post/link photos. They took down the photos once I bought it. But they are cached on cars.com.


Sorry, only registered users may post in this forum.

Click here to login