$7.00 a gallon, I wish. It is now $8.50 a gallon.

Poltarf

GearheadGeek

Obviously this suggestion came from someone who lives in the the crowded Northeast as opposed to the wide open West. Some of us like to get to where we are going on the same day.

Rusted

Papa Midnight

Papa Midnight

Dave, they do exist, at least here in AZ. I received one one time by a highway patrol officer. Instead of him giving me a speeding ticket, he gave me one of these. Only a $35 dollar ticket IIRC. The ticket is labeled as "Waste of a finite resource in short supply".

kidgenius

At 55 I have to run in overdrive or double overdrive at 1500 or 1200 rpms respectively. Don't blame me, blame the 47RH. This gets me between 8 and 9 MPG.

At 75 I run in double overdrive at about 1675 RPMs. This is more into the torque and hp curve of the motor, and as such, it is more efficient. I get between 11 and 12 MPG here.

Past 80 efficiency goes back down, though it will usually stay in the 9-10 range until 85 or so which is still better than 55.

This is a blanket statement, and its completely false. Because of an inability to re-adjust braking and efficiency curves in the US, we're stuck with a) speed limits that are far lower than they should be, and b) people running around spreading lies like these. This report should say that efficiency decreases past 75, not past 60.

The railroads re-adjust their speed limits based on braking curves and fuel efficiency every couple of years. Why is it so hard to do the sameon the roads?

RamV10

rodeo40

CapitalC

Optimistic Prime

Orv

Highway patrolmen concentrated on removing asshats and little old ladies who were obstructing traffic.

When a federal judge set the speed limit at 75 by judicial fiat, the fatality rate went up.

kbarrett

Do you mean having speed limits at is okay, or just the level at which they're set?

Because you need to travel more if you think surface street speed limits aren't fucked up in half the cities in the US.

TechnoDestructo

This reminds me of
"Knowledge is power"

Plug these into the equation for power:
power = energy / time

And you get
knowledge = energy / money

Assuming a constant personal energy level, as money increases, knowledge decreases.

Conversely, as knowledge increases, money decreases.

Hence, engineers get paid less than corporate executives.

Optimus

That's not what is at issue here. It's whether your car is at its most efficient at the same speed at which a completely different car is at its most efficient.

You're right in that different engines, different gearing, and different aerodynamics mean different cars will have different results, but we're not talking about the overall efficiency of small cars versus large trucks.

Oh, and if I can get 28 mpg (versus the EPA's old 24 highway, or revised 23) with the cruise control set at 75 in my 96 T-bird, I think I'm content to set it at 75.

TechnoDestructo

My membership pays for itself in coffee beans and olive oil over the course of a year, the rest of the savings are gravy.

GearheadGeek

$2.60 * 52 weeks/yr = $135.20

Most people have 2 cars(or more), so now you are at $270.40 in savings for the year. Costco membership currently costs $50. $220.40 saved in a year? Cool in my book.

internal

AD8BC

In general, I don't mind other people speeding (I dutifully putter along in the right lane and ignore anyone tailgating me), but it really scares me seeing all the near misses on the interstate due to tailgating and aggressive speeding.

I would definitely recommend people try to be more conscious when they're driving and question why they are furious at the person in front of you who is going slowly. Why are you so angry? Why are you in such a hurry? Is it worth getting so worked up about the situation? Is this safe? I used to have a lot of problems with road rage and feel I have really helped my life (and my wallet) by addressing it.

wwwhitney

Jinx

FWIW power required to overcome drag

Pd= 1/2pv^3ACd

That is power used is on the cube of velocity for a given car while frontal area and Coefficient are merely linear functions.

Fuel usage is roughly proportional to the amount of power required. (Mind that you need to worry about other frictional losses as well)

Geekybiker

FLConsumer

I disagree with the typical legal definition of "above the posted speed limit." Instead, I propose that speeding is "driving faster than conditions warrant." Of course the law doesn't care for this wording as it's highly subjective, but so is driving. I know what my car is capable of, and more importantly what it's not capable of. I also am fully aware of what I'm capable of. I drive slower when I'm tired, feeling sick, or just not 100% focused on driving.

I still have yet to understand the logic of how they determine the speed limits for roads here. Quite often I see what appears to be speed limits set for blatant speed traps. The main road near my house pulled in nearly $300K in speeding tickets. 4-lane divided highway, straight shot w/no side streets for 5 miles. 45 mph speed limit. Compare this to the main street by my other home, 4-lane divided highway, side streets every 1/4 mile, 65mph. Both have approximately the same traffic levels and congestion.

I almost never drive 65mph on the 65mph road as, even by my own standards, it's too dangerous. That's saying quite a bit considering I don't mind hanging around the 'century mark on the highway if I'm the only car for miles. The 45mph road realistically should be at 50mph or 55mph. BUT, considering they pull over ~30-100 motorists a day on that stretch of road 24/7, 365, I'm not about to do it. Constantly looking down at my speedometer is NOT safe driving, especially in heavy congestion.

Ultimately, cars at differing speeds are what cause accidents. If everyone's going the same speed, there's little chance of running into someone else. The problem comes up when you set unrealistically low speed limits and then have people driving as fast as they feel they can risk before getting a speeding ticket. Everyone's acceptable risk level is different, thus the huge speed differences we see on the road. Set realistic MAXIMUM speed limits (not average) and enforce that.

Better, enforce the real causes of accidents -- asshat-like driving. Tailgating, weaving in and out of traffic, not using directional signals, unsafe vehicles,things falling out of vehicles/not tied down properly, etc. I know the average traffic cop has the mentality of a dog and chasing cars is fun, but doesn't do anything for actual traffic safety.

FLConsumer

AD8BC

Papa Midnight

Papa Midnight

LionelEHutz

A great example is when Mythbusters filled two identical trucks with the same amount of fuel, left the tailgate down on one and up on the other. The vortex in the bed benefited the one with the tailgate up, and got measureable better mileage. This result is contrary to the normal human logic, but only because we don't normally see the air moving.

Another Mythbuster episode shows the best way to get good mileage: tailgate at a 24" distance behind a large truck. And wear a helmet, just in case.

okvol

Going slow also keep the blood pressure low.

theravenfakeaccount

lonewolf333

You would be correct if you only considered conditions where you drive in a vacuum. Regardless of the shape of an object, aerodynamic drag increases exponentially with the speed of the object. All other mechanical considerations (rolling resistance) increase roughly linearly. So at some point, the amount of power used to overcome wind drag starts to increase rapidly in comparison to the amount of power used for rolling resistance. For most cars, the equilibrium point is around 50-60 MPH, depending on the shape of the car.

Below this value, most of your engine power is to overcome friction and mechanical factors, and those are the dominant factors in your fuel efficiency.

Beyond that, you are increasingly expending proportionately more fuel to overcome wind resistance, which overall reduces the fuel efficiency of your car. There *is* some magic number around 60 MPH after which the power needed to maintain a particular speed increases exponentially universally for all vehicles, but how this affects fuel economy is a slightly more complicated question.

ludwigk

lonewolf333

You can try blipping the throttle while in neutral and then shifting to first. You should actually do that every time you downshift...when you're in between gears on a downshift, give the gas pedal a tap so that the engine speed and gear speed match, and then downshift. That'll keep the car from lurching or bucking.

A.W.E.S.O.M.-O

As an aside, what is wrong with American-brand cars? They get the WORST mileage. My luxo-barge outfitted with all of the electronics & extra air con pulls about 22MPG in Tampa traffic (~24MPG in other cities which have synchronized traffic signals). Drove a rental Ford Tarus around town for a bit when my car was in for one of the major services and I was getting 18-19MPG with it and I wasn't treating it harshly. If anything I was driving it lighter than I do my own car as it was practically brand new (<100 miles on it). I've noticed this with just about any American car I've had as a rental in other cities as well. It's not like these cars had 4.5L V8's or all of the extra equipment I carry on my own car. I'm not a conspiracy theory person by any means, but it does make me wonder if the US auto makers get any sort of kickback from the oil co's on this. Their mileage is just so substantially poor that I'd hate to think this was the best they could do.

FLConsumer

So, you're saving two and a half bucks every single week. Awesome.

inzain

GearheadGeek

Shadowman615

I've never noticed getting any better fuel economy when the tank was getting near empty.

As for the magic speed where my fuel economy starts to drop off, it is above ~70 in my Mazda. In the Jeep it doesn't seem to matter if I drive 60 or 70, it still will only get about 19-21 mpg on the highway.

barty

The one big difference I noticed in Europe is that people tend not to live 40 miles away from where they work. There has not been enough attention to this in the US. Someone who burns 40 gallons a week in his hybrid driving to a far off job is a hero. A soccer mom who burns 20 gallons a week in her Tahoe going to the grocery store is an environmental terrorist.

My point was that we still pay some of the cheapest prices in the world for gas. People here act like $4.00 a gallon is the coming of the apocalypse.

bdgbill

My motto is, "Better late than late." (The first means time, the second means dead.)

KJones

Bladefist

When I'm slowing down for people crossing the street and I end up in neutral while going at 2-3MPH, the moment the road clears, if I go on 1st, it's too much. If I go on 2nd, it's lugging. I need a motherfckn in-between gear!

ninjatales

You want to blame someone, blame the Eisenhower administrator for the simultaneously best and worse decision for the US economy: The National Interstate Highway System.

radio1

lonewolf333

ClayS

@cynon: You don't remember 70's well. During Carter's administration, gas and oil products simply increased in price; they are considered "the little gas crisis" of the 70's. The big ones were in '73 and '74, where people could only buy gas on alternate days and gas stations ran out of gas every day. The 55mph national speed limit was instituted by the Nixon administration in '74.

radio1

QFT

Tzepish

But correct, there is no magic speed.

ClayS

Papa Midnight

I'll worry about speeding tickets and insurance, I get good enough gas mileage that the rest is a drop in the bucket.

AustinTXProgrammer

shekondar

redhelix

CNN Money is completely full of shit. There is no arbitrary speed that suddenly wastes more gas than any other speed. The volumetric efficiency of an engine as determined by its design, coupled with the gear multiplication of the driveline, the car's aerodynamics, the engine's RPM, the vehicle's weight, and a dozen other physical attributes is what determines the efficiency, not some arbitrary pulled-out-of-their-asses MPH number.

"It's not facts. It's CNN Money."

sgodun

[www.cockeyed.com]

Pasketti

geeniusatwrok

lonewolf333

lonewolf333

mc101

crapple

Bladefist

thebaron

lonewolf333

I call bullshit on their numbers. Perhaps if you consider a crossover or SUV the "typical family sedan" in the US, this is true. It's definitely true that going faster tends to require more fuel, but this effective difference of $0.54/gallon per 10 mph over 60" doesn't wash.

I drive an '05 Subaru Legacy GT Wagon. It's similar in size to a Camry or Accord, so it's right in line with the "typical family sedan" sort of car. It's AWD and turbocharged so it's quite a bit more fun than either an Accord or a Camry, but fuel-economy wise it's around what their V6s return, which again is pretty typical, though I think they sell more 4cylinder cars than V6.

Using my observed fuel economy over the 45k miles I've driven the car, and assuming a price of $3.30/gallon (reasonable price for Super around here) I find that the first 10mph (70 mph) costs me around 1mpg (highway) which represents an effective increase of about 12.7 cents/gallon. Bumping that up to 80 mph costs me about 3 mpg (over 60 mph) for a total increase in 20 mph of about 41 cents/gallon, so that last 10 mph cost me about 28 cents/gallon.

Now, bumping it up to 90 mph, the incremental cost goes up sharply to about $1.20. THAT is how they get their "$0.54/gallon" bullshit number, but they conveniently avoid saying that there's very little incremental cost for driving 70 mph instead of 60, it's when you get up above 80 mph that it really starts to cost you.

GearheadGeek

Those who do not learn from history (Can you say oh... ANY OIL COMPANY?) are doomed to repeat it.

cynon

I've been tracking my gas milage religiously since my first car (1979 VW Rabbit) and with the advent of the in car computer here is what I have found.

My former car was a 2003 BMWE 325ci manual transmission. This car was designed with both American and European highways in mind. As such (according to the onboard computer) it was most efficient at 70mph and there was little difference between 60mph and 80mph. While it does take more fuel to reach those speeds, as long as you are using cruise control, that efficiency can be recouped by maintain a consitent speed and arriving at your destination sooner.

My current car is a 2007 VW Eos with a 2L 4cyl turbo charged engine. This car's gas milage is not nearly as good as the BMW, espcially during acceleration. However, my most efficent speed is 65mph with a big drop off past 70mph.

For those of us that are concerned with the price of gas and drive with conservation on the brain, it is important to understand the ins and outs of your own vehicle. If you are looking for a new car, the on-board computer really helps, and if you have an older, ask the dealer or service shop. They may know what speeds are the most efficient for your model.

dfellars

I know another idiot who waits in line at Costco to buy gas every weekend so he can save (maybe) three cents a gallon. On this guys car that amounts to a whopping 30-40 cents saved total.

That's funny. A Costco just opened near my house (first in the city, actually) and I went there for gas today. Paid $3.09. As I was pulling out, I noticed that the 7-11 across the street was selling gas for...wait for it...$3.09. I don't think I'm going to be going out of my way to go there for gas anymore.

Peeved Guy

Well, tough crap, the speed limit here is 75.

rmz

bbagdan

People are nuts about the price of gas. If gas going up a dollar is bankrupting you, you either have too big a vehicle or live to far from work.

I used to work with an idiot who would proudly tell anyone who would listen that he "shuts his engine off when going downhill to save gas". I know another idiot who waits in line at Costco to buy gas every weekend so he can save (maybe) three cents a gallon. On this guys car that amounts to a whopping 30-40 cents saved total.

Everyone needs to take a breath on the gas price issue. There a are a couple hundred million people in Europe paying $7.00 a gallon for gas and their economy is doing a hell of a lot better than ours.

bdgbill

truthie

If you want to go 60mph, fine. Just be sure to stay in teh slow lane.

BMRFILE

Of course, what people are failing to factor in when promoting speeding is that gear ratios of most cares are not designed to travel much above 60mph (or 70 mph for some) efficiently. Once you hit the upper limit of the speed for a given gear ratio you MPG start to drop.

Edidid

SLOWER TRAFFIC KEEP RIGHT

This lets the speeders save time in the left lane. And this lets the gas misers save gas in the right lane. And we all drive happy.

LatherRinseRepeat

On my brick-of-a-frontend Subaru, yes, this is true. (Roof racks and a turbo don't help either), and I consume more fuel at higher speeds.

On my Z3 Coupe', however, I get best instantaneous and cruise mileage at about 73mph. Of course the car is much more slippery, and is geared for Autobahn cruising. It will pull past 100mph in 4th gear, so cruising in a heavy-overdrive 5th, the engine is basically yawning at freeway speeds.

MikeHerbst

Bladefist

Yeah diminishing returns kicked in at some point. But most of the improvements were still in the danger area.

I think you may be right in that it was 5 foot was the best, then 2 foot showed decrease. (Originally thought 2 was best, and 1 showed the decrease)

Its been a while since I saw that episode.

godai

NotATool

bonzombiekitty

A.W.E.S.O.M.-O

So the question is, what's more important, time or money?

My answer: time. By a long shot. Wanna change it? Tell every employer in America to stop demanding more time from their employees. Evenings, weekends, nothing's sacred anymore, and I need all the time I can get.

humphrmi

Dobernala

Peeved Guy

A car is a system, and changes to one part of the system cause changes to other parts of the system. You can't take one thing and say that's they key. For example, if everyone went 65 and drafted the car in front of them, they'd save gas... and probably wind up dead when the lead car hits a deer.

NefariousNewt

axiomatic

Bladefist

I thought mythbusters showed diminishing returns...

that 10-20 feet behind a semi-truck was optimal...and that at 5 or 2 feet you actually burned MORE gas. Right?

@A.W.E.S.O.M.-O:

Did more googling...apparently...less fuel in the tank means more wear and tear on your fuel pump. So you might save money on less gas...but then more than pay for it when you have to replace the fuel pump on your vehicle. I'll just stick to cruise control and hyper-miling (only the legal tips and tricks...because some hyper-miling suggestions are NUTS....and illegal).

ConsumerAdvocacy1010

qwickone

Crrusher

Bladefist

Turns out, because I had gotten a speeding ticket soon before my trip, I was much more cautious and therefore slower on that particular trip home. By traveling at about 69mph instead of the (admittedly hight) 78mph I usually traveled, I saved about 25%-ish worth of gas. Since then I never go faster than that.

karmaghost

badgeman46

Didn't Mythbusters already do this?

And why don't people just drive with thier front bumber 2 feet behind a semi when driving. Since that greatly increased the milage? (That was definately on a mythbuster.)

godai

BlondeGrlz

That70sHeidi

Murph1908

Driving 60, I can get 48 MPG in my regular '07 Civic. So it's worth a try if you're not in a hurry. Just don't whine about gas prices when you're blowing by 80MPH+ in your Tahoe. :P

EBounding

I just went to look at the auction. Some pieces that stood out and made me laugh:

In scrolling text "Buy with confidence. Call Michael at 402-802-2272"
So much for confidence, Mikey.

In a Title field in the auction, "Lowest price on eBay."
Seems the low price was meant to be a draw to the auction.

In the About Us "Our Dealership has built a reputation on providing courteous, honest service. Our customers appreciate the way we do business, and we know you will too."
Ha! That's classic.

Murph1908

With that said, I'm willing to pay extra to get where I'm going faster. Opportunity cost FTW.

A.W.E.S.O.M.-O

warf0x0r

Tomorrow can we publish an article such as "All black people steal" or something to that effect?

trickonion

okay...did some googling...

Average gas tank size is approx 17 gallons.

1 gallon of gas = 6.15 lbs.

Half tank of gas = 52.275 lbs.

According to AAA and other sites...every 100 lbs reduces fuel economy by 2%. So half filling the tank can improve fuel economy by about 1%. Couple this with some hyper-miling techniques and it 'might' be worth it.

ConsumerAdvocacy1010

ARP

privatejoker75

"Any orger a pair of exploding pants?"

Classic, sheer classic watching poor Buster getting nuked when those pants blew up.

Nighthawke

Anyone?

ConsumerAdvocacy1010

mattatwork

Maybe we need "You're wasting gas" tickets.

Now? I do 75 mph. If I get yanked for the 5-over, I'll gladly pay it.

davelawrence8

jeblis

badgeman46

SomeoneGNU

ClayS

Peeved Guy

scarysnow

oakie