What's Your Car's Gas Milage? Poll

[Danger]

Okay, I'm at work now. Pardon the delay... there were things to do when I got here--damned customers .
Anyhow, the major unique thing about it was the engine itself. All that I knew when I bought it was that it went like stink. Going by the VIN, it was the hi-perf 440. (The options were the standard or the Commando.) That indicated the 4-barrel carb, 10:1 compression, and 295 hp. (It's a GTX, by the way, but that package deals with suspension, brakes and cooling.) The factory redline was 5,500 rpm, but it didn't really start making power until 5,000. My rule was that the valves floated at 6,500 so I shifted at 6,400. It's an A-833 4 gear tranny with the long-throw Hurst pistol grip shifter, going into a 3.23:1 Dana 60. If I were going balls to the wall, I shifted to 2nd at 65 mph, third at 85, and 4th at 115--and 4th is a .73:1 overdrive. Top end was 160 mph. The estimated hp by performance (never dynoed it) was about 390.
440's don't particularly like to oil the #4 rod bearing for some reason, and the damned thing spun out on me whilst on vacation. The piston collapsed and took the bore with it. Hence the rebuild. When we took it apart, it surprised the hell out of us to find that it had 6 10:1 pistons and 2 8:1's. Also 6 4-barrel rods and 2 Commando ones. The odd rods were not linked to the off-spec pistons. The only explanation that I can think of is that it was the builder's way of balancing the motor. If so, it worked; the thing ran like a turbine at 6,000+ rpm.
And as for the paint job, Cyrus, it's getting the same one that's on my pool cue. If I can get it to show up properly, I'll post a pic. Starting at the front, it fog-fades from emerald green through teal, deep royal purple, and finally black.

edit: I just saw your post, Woolie; you sneaked it in while I was typing mine. As you've probably foreseen, my response is .

2nd edit: Cyrus, there was something nagging me about that picture, but I didn't realize until now what it was. That's a '73; mine's a '72. You can tell because the side markers are 3-section jobbies and mine are single.

 

[Cyrus]

Yeah, I realized that too. I like the 73' body personally.

As for the 3 color paint job, ehhhhhhhhhhhhhhh. I don't know if that would look proper on a muscle car. I'd stick with solid black. Nothing looks sharper than a solid black car.

http://classiccars.kfunk.net/plymouth/72plymouth_roadrunner.jpg

Meep Meep.

 

[Danger]

And nothing's harder to keep clean.

 

[larkspur]

Yeah, I realized that too. I like the 73' body personally.

As for the 3 color paint job, ehhhhhhhhhhhhhhh. I don't know if that would look proper on a muscle car. I'd stick with solid black. Nothing looks sharper than a solid black car.

http://classiccars.kfunk.net/plymouth/72plymouth_roadrunner.jpg

Meep Meep.

That's it!

 

[JasonRox]

There's no 'legal' limit to horsepower.

I never said there was one.

You must have Dyno Sheets to back that claim. And no one throws away 2000HP Dyno Sheets.

 

[Danger]

You misinterpreted the statement, Jason. I haven't built the thing yet. 2,000 is admittedly a rough estimate, but I know for sure that it'll be over 1,800. It's not at all unreasonable when you consider that a lot of street rods are well over 1,000 using more conventional and much smaller engines.

 

[JasonRox]

I can't see it happening though. Not with an old muscle car.

Your best shot would probably be like a Corvette engine rebuilt with a massive turbo strapped on, but even then that would be tough.

 

[Danger]

Your best shot would probably be like a Corvette engine rebuilt with a massive turbo strapped on

 

[wolram]

You misinterpreted the statement, Jason. I haven't built the thing yet. 2,000 is admittedly a rough estimate, but I know for sure that it'll be over 1,800. It's not at all unreasonable when you consider that a lot of street rods are well over 1,000 using more conventional and much smaller engines.

I hope to get the power of 35 horses from my tuned velo, it is going to have special crack cases, a pollished con rod, an 8 to 1 piss ton, a hairy cam, a light head, oh yes and trendy followers.

 

[Cyrus]

Oh baby, check this out Danger.

http://cgi.ebay.com/ebaymotors/1971-Plymouth-Road-runner-440-6-pack-V-code-rotisserie_W0QQitemZ4652022135QQihZ002QQcategoryZ43921QQrdZ1QQcmdZViewItem#mainImage

This is your car in its original condition 71', she's a beaut.

 

[Danger]

Jeez, that's sweet! I must have been mistaken about '73s having the split side makers, because this one does. In most other regards, other than colours, it's sure almost identical to mine's original look. Mine, however, didn't have the deck spoiler or H-pipe, it had the air shock tits sticking out about an inch from the bottom of the rear bumper, and there were the mags on the back instead of factory rims. Also, the body trim was different and the emblems weren't in the regular locations.
Thanks millions for the links.

By the bye, one of my friends who watches the auction in Vegas told me that one just like it went for slightly under $100,000 US last fall.

edit: For Jason: My design is based upon the 'kangaroo' motor. If you can find anything about it, you'll know what sort of monstrosity I'm planning.

 

[Skyhunter]

I have an 82 VW Rabbit pick-up. I get 42-44 with diesel fuel, 40-42 with bio-diesel. It had a SVO conversion but it was disconnected so I removed it, found that bio-diesel was more convenient.

 

[Danger]

I have an 82 VW Rabbit pick-up.

Tell me again why I continue to let you live on my planet?

 

[Cyrus]

AhAHAHA, I am watching shaft right now (original). Hes rolling around in his red roadrunner. You damnnnnnnn right!

 

[Danger]

Believe it or not, I've never seen that movie. Guess I'll have to check it out.

 

[Rach3]

I think we should be using gpm instead of mpg. The savings in going from 8 mpg to 12 mpg, is much greater than in going from 28 mpg to 32 mpg, even though the "difference" is the same, 4 mpg. The more logical system is clearly linear in fuel. I mean, who here, when driving, thinks to theirself "well, I've decided to use 2.37 gallons on this trip, so where will I go?" Rather, we think "I'm going to X today, so how many gallons will I use?" Who agrees?

8mpg = 0.125 gpm
10mpg = 0.100 gpm
20mpg = 0.050 gpm
30mpg = 0.034 gpm
60mpg = 0.017 gpm

 

[Rach3]

The mpg system we're using understates the economic impact of things like Hummers. We should be using a language in which "Hummers use ten times more fuel than small cars" is a common phrase, not meaningless statements like "X" gets 20 miles more than "Y" to the gallon. (relative to what?) I think this is really necessary, since very few Americans really understand how deal with an inverse measure like mpg, so they have no ability to make smart decisions about this.

 

[Cyrus]

I think they have the ability to make these decision. Your GPM system is awkward and inconvenient. Its all in decimals! No thank you!

MPG is relative to one gallon. So what? GPM is relative to one mile! That's not any more linear than MPG. I don't buy gasoline by the mile...

A side, where do you live Rach? I thought you were in Europe?

 

[Rach3]

A side, where do you live Rach? I thought you were in Europe?

I'm obviously an American, where else do people have to live with Hummers on their roads? (aside from Iraq and Afghanistan...)

 

[Rach3]

I think they have the ability to make these decision. Your GPM system is awkward and inconvenient. Its all in decimals! No thank you!

Multiply it by 1000x and call it "Gallons per thousand" (gpt). Then you have the same range as with mpg, and things look like this:

10-15 gpt - motorcycles
~15 gpt - hybrids
~30 gpt - small cars
~50 gpt - medium-sized sedans
80-120+ SUVs

Puts things in perspective.

 

[Cyrus]

No, your making things way to complicated! Gallons per thousand miles! This is getting lame!

Like I said, no one buys gasoline by the mile...

 

[Rach3]

And no one buys miles by the gallon.

 

[Cyrus]

What, buys miles? Buying miles makes no sense.

Yes, when you go to the station, you buy x gallons of fuel. Your car gets Y MPG, you can drive XY miles. Is that so hard?

Now your system:

You buy x gallons of fuel. Your car gets Y=1000/Z MPG. Now I have to find out how far I can go, 1000*X/Z...

No one in their right mind would want to use that system!

It's LAME!

 

[Danger]

Well then, let's simplify it and go with our Canuk way. Litres per 100 kilometres.

 

[Rach3]

Or we can do fuel efficency in inverse hectares...

My point is this: what we really want to measure is some sort of "rate of fuel consumption", not this "inverse rate of fuel consumption". How much will fuel cost per year? You multiply X thousands of miles by Y gallons per thousand-mile, and get a figure of gallons. This is practical. The scale is linear in the quantity of fuel. This strange "mpg" system depends inversely on quantity of fuel.

Measuring the number of miles between gas station trips to make decisions is, IMO, a myopic way of doing economics.

 

[Cyrus]

No, there is nothing "strange" about it, and it is linear.

You can plot the miles you will get as a function of the number of gallons of fuel. It is a system based on the number of GALLONS not miles, because we purchase GALLONS of gasoline.

Where are you getting this 'inverse' relationship from?

This is middle school math...

y=mx+b

y-miles
m- MPG
x-#gallons in your tank
b= 0 (no gas, no miles)

You are making such a simple concept wayyyyyyyyyyyy too complex my friend.

The fact is, no one cares about how many gallons to the thousand miles.

 

[Rach3]

What I mean is

$$\mbox{gallons of fuel } \propto \frac{1}{mpg}$$

for a trip of definite length, and vice-versa.

 

[Cyrus]

But I told you ten times now, no one cares, because no one pays by the mile man!

 

[blue636]

When I had my Kawasaki EX500, I got about 57-60mpg. On my Suzuki SV650S I get about 44. On the Kawasaki ZX6R 636, I'd get about 36-38 mpg.

 

[Rach3]

Cyrus:

Perhaps I am blind, but I really have no idea what you mean by that. People who buy hybrids don't suddenly start driving three times more often; people who buy SUVs don't drive three times fewer. Trip lengths are not a function of fuel efficiency, they are function of how far apart destinations A and B are and what roads are in between them. So a consumer will driver more or less X miles a month, regardless of what they're driving in. We can treat that length as a constant, because it is independent of the mpg rating.

Now, as far as my meager brain can fathom, the economically interesting number here is how many dollars the consumer is spending on fuel. Since the trip lengths are constant, this rate of spending goes as to

$$\mbox{spending } \propto \mbox{gallons of fuel } \propto \frac{\mbox{distance traveled }}{\mbox{ fuel efficiency (miles per gallon)}}$$

And as long as our consumer isn't drastically changing his driving habits, the distances involved are constants:

$$\mbox{spending } \propto \frac{1}{\mbox{ fuel efficiency \bf{(miles per gallon)}}}$$

Hence fuel efficiency goes inversely as to our economically interesting quantity, the $.

Now, if we were to use a more sensible fuel efficiency, gallons of fuel per distance, the above equations become

$$\mbox{spending } \propto \mbox{distance traveled } \times \mbox{ fuel efficiency \bf{(gallons per mile)}}$$

Which is nicely linear in fuel efficiency.

 

[Cyrus]

I give up, I am going to go drive my car into a wall sticking my head out the window

 

[Rach3]

I give up, I am going to go drive my car into a wall sticking my head out the window

And you made this decision without thinking about said car's fuel efficiency! That supports my point!

 

[Rach3]

Actually I suppose it would be called "fuel inefficiency", but I still think it's the more interesting number.

 

[Cyrus]

Ok, replace wall with you. I am going to drive into you (with a hummer that has a leaky gas tank)!

Look, my car has a 13 gallon tank. It's going to cost me 13*(going price of gasoline) each time I fill it. THATS what I care about.

I know that each time I fill my tank, it will cost me that much money, and I can go that far on that full tank of gas.

Why on Earth would I want to start calculating my average trip length, multiply that by 1000, divide that by MPG!?

 

[Rach3]

Look, my car has a 13 gallon tank. It's going to cost me 13*(going price of gasoline) each time I fill it. THATS what I care about.

But that's just the point! How often will you be filling it?!