Gas Prices and Driving Speeds

Everything is bigger in Texas.........including a Texan's estimate of how big things ARE !!

Dear Double,

I had responded to something that was subsequently removed by management. Sorry about the confusion.

david

Dear Ka,

I always find that Bill Moyers' estimates are right on the mark. I had similar feelings for the great mind of Barbara Jordan and although I had one big problem with LBJ (the war), I loved his acuity and enjoy hearing the old dictaphone recordings of him twisting the arms of Congressmen over the telephone (I wish that CSPAN would let me know if they are going to play those again). For sheer presence of mind, those three are giants and all are from Texas.

I am eagerly waiting to hear the estimate of driving time from London to Inverness from our good brother in Dallas.

david

Hello David,

Been to London many times, and always enjoy the place (except the weather). I am used to driving to Luton, which is just like driving from Dallas to Fort Worth (34 miles each):

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=london,...

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=Dallas,...

As far as the driving time goes, from London to Inverness (560 miles) would be a short drive of 9 hours and 45 minutes:

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=london,...

In comparison to John O'Groats to Lands End (874 miles), the distance between Texarkana to El Paso (both in TX) is 812 miles as well:

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=texarka...

Moon

London to Inverness, only 9 hours and 45 minutes:
http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=london,...

Two extra hours to drive from one end of Texas to another:
http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=texarka...

I guess, I was being humble in saying earlier that it takes 8-10 hours to travel across Texas

Moon

... I hope that I have not disappointed either one of you

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=brownsv...
Brownsville to Stratsford.... 14 hours

Dear HF,

I find your thesis about automobile safety most interesting. It made me consider the construction of these machines.

Quite a few years ago when my mother bought a new car, she gave me her old one: a 1969 Lincoln Continental Mark III. Some folks call their car a tank but this car was a tank. The bonnet (hood) was so long that it felt you were driving from the back seat and the relatively small windscreen added to the effect. It contained a 460 cu. in. engine that moved the machine like a jet (albeit a B-52 and not a F-111). "Bench seat"? Nah -- lovely brown leather seats with electric controls to move it in all kinds of directions. And yes, it had seatbelts.

Now we come to the good part of the story. My mother told me that she had once seen another Mark III at the dealership that had been hit by a truck. There was a slight denting in the front. I must tell you that when I would knock on the metal of the car, it would sound like "thunk, thunk, thunk" -- not "ping, ping, ping". You could not dent the metal by kicking the car with boots let alone leaning on it.

Of course, one imagined that one could see the gauge for the tank go down as one pressed on the accelerator. However, if I were going to be in a collision, I would much rather be in that car than any of the other cars I have driven (I have driven quite a few in the last forty years) notwithstanding crumple zones et hoc genus omne. If fact, this is truer today than it was when I was driving that tank as all too often I have to slow down when some SUV seems to want to mate with my Subaru Outback from behind.

As the AWD (all-wheel drive) does not create good fuel economy, I am researching which hybrid I may want to buy in the next couple of years. I am leaning towards the Camry, which has good crash tests according to Consumer Reports; however, in an actual crash, I would rather be in that 1969 Continental Mark III.

david

P.S. How many two-door cars weigh two and a half tons?

Speeding just gets you to a gas station faster and gas stations are not where we want to be.

Don't want to be there either..

Dear Moon,

I image the Texas authorities will let you speed faster than the British police. However it is still hardly a "matter of minutes." How many of those "few hours" will it take you to drive from one end of the country to the other?

Your brother with the Valentine One, david

P.S. I am going upstate later this month and shall be going into Canada. I cannot use my V1 there. Here in the US, it is only Virginia and the District of Columbia that forbid using it.

Thank you for this information, Apo.

With virtually the same driving time, the maximum distance between two towns within Texas is 868 miles, and within UK is 818 miles:

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=penzanc...

Anyone wants to take a stab at the maximum driving distance between two ends of US?

Moon

http://maps.google.com/maps?f=d&hl=en&geocode=62199175437341...

Or driving VERY fast.

NB: Trying to drive a Chevy Blazer from Houston to El Paso in 10 hours or less will result in a dead Blazer, somewhere in the vicinity of no-where, or Ft. Stockton, whichever is closer.

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=Belling...

Bellingham to Bangor

http://maps.google.com/maps?f=d&hl=en&geocode=&saddr=Belling...

Honestly David, I know that most signals in London have the red light cams, and the disobedients receive the gift in the mail. However, I am not not very familiar with the police on the motorway there? Are they also in the hideouts with speedguns/radars to get those speed demons, or do they mostly have speed sensors with cameras to regulate the speed?

And no, the Texas authorities would definitely not like me to speed (faster than British police). However, two factors (TX being mostly flat, and my faithful Valentine one) have enabled me (at times in the past) to drive down the highways at LITTLE over the posted speed limit

Finally, it will take me less time to get from one end of UK to another, as compared to one end of TX to another

Moon

The unfortunate thing is people that have the big SUV's don't give a darn about Gas prices, or they would have bought that gas guzzler in the first place. Lots of people don't feel the pinch, they have multiple incomes and could care less that you or me have to worry about two or three miles per Gallon.
The sad reality is this, the Gasoline prices are going to remove the middle class from our society, there will be the Haves and the have nots. So we can complain about gas prices all we want and tell people to slow down, but the have's don't care.

Bob

People who can ARE using public transportation more now in the U.S. Amtrac WAS underutilized NOW it has expectations of not being able to meet demand. Many people in cities with good public transportation were formerly using cars but now are switching to trains, buses, subways. There has also been a reduction of people moving to houses in the suburbs, maybe even some people moving back to the cities. People who HAVE to drive are switching to more fuel efficient cars. Price affects behavior. Even combining errands to make as few trips as possible will help reduce the use of fuel.

What the Chinese and people of India (Indians?) do matters, of course. But right now the U.S. uses 25 barrels of oil per year per capita. The Chinese use 2, Indians 1. If that article is correct, the Europeans use about 8.

Dear Moon,

My faithful V1 has been great too. I bought a V1 in 2000 and it has served well. A few months ago I was looking at the V1 website and saw they offer upgrades if necessary when you put in your serial number. I called Customer Service and the representative told me that my unit was still fine until I told them I live in NYS, which is one of those places where POP is now being used. He said it was probably still OK for most situations but I decided to upgrade to the newer version.

The upgrade is about half the price of someone buying it new and I sent in my old unit and received the new one by two-day delivery. It is thinner (only one inch thick against one and half in the old unit) but otherwise looks to be the same sturdy design and the other dimensions are the same as well.

I too am sometimes a "LITTLE" over the limit but only when following a pace car at some distance -- never a truck, which might block signal. One must also never allow anyone to tailgate when doing this as one may have to apply brakes without warning.

david

cheers to that

I have heard that it is a myth that gas mileage would improve if the max speed limit was reduced to 55mph (as was the case for many years after the gas lines of the mid 70's). What I understand is that most cars today are designed to deliver maximum fuel economy at 65 to 70 mph, and that mpg would actually be less at 55mph.

Dear David:

We were in the same shoes. However, by selling the older V1 on eBay (to someone who didn't even care/need POP) and buying a new one myself, I had saved over $100

Moon

Dear Moon,

I am happy to hear you were able to sell the old unit for such a good price. V1 is, of course, the best as the others do not provide the direction of the signal, which can be most instructive.

david

This may sound ridiculous but recently I was on a drive from Viking AB to Vulcan AB traveling approximately 70 MPH. In Red Deer I figured out my gas milage and it was 18.1 mpg. Something urgent came up and I ended up traveling 80-85 MPH for the remainding 2.5 hours of the drive and my average fuel economy increased by a full mpg, 19.1 mpg after the total 4.5 hour drive. It sounds crazy but I witnessed it first hand.

"I have heard...." is right up there with "They say...."

There may be a few isolated cases where that is true but, in general, slowing down does decrease gas consumption, all the way down to where the transmission shifts out of overdrive.....about 45 mph.

Unfortunately, there is no isolated case that is true. It is just simple law of physic. Air resistance (drag) applies to everything. It takes energy to over come it. Find me a car that can get better milage when it goes above 55-60MPH. I'll buy it.

And you know that becasue.......????
You have access to wind tunnel tests for every car and truck ever made ???

That is a reasonable assumption but you don't KNOW any such thing.

In general, the power needed to push a car through the air goes up with the cube of the speed. (So to go twice as fast, you need eight times as much power (2**3 = 8)).

http://en.wikipedia.org/wiki/Air_resistance

So, twice as much power is required to travel @ 70, compared with 55. [(70/55)**3 = 2.06]

However, I suppose it could it be possible, that on a particular vehicle, (depending on the gearing), that the engine is operating in a more efficient part of its rev. range @ 70? There would have to be a major discrepancy in efficiencies, for it to make up for the extra loss due to air resistance.

(I always understood, that petrol engines give best fuel economy at the same revs. that peak torque occurs at.)

By way of introduction, I live in Canada and gas prices are approaching $1.50/litre or $5.60/US Gal. Today I paid $1.33 ($5.02). I can afford the gas I need, to go where I want, at the speeds I want. I also drive at whatever speed I feel comfortable with at the moment. I had my bike up to 185kmh (115mph) the first day I had it just to see if it could and frequently drove MY car (Olds LSS -RIP) with cruise at 175kmh (110mph).

However, I choose to drive conservatively most of the time simply because I've always driven that way. One of my normal long distance trips is Ottawa - Toronto and there are basically 2 routes I can take, Faster or Shorter. (this is a GPS related forum after all). Taking the Faster route is 378km to my destination and takes 4hours according to the Garmin. Taking the shorter route is 338km and takes 4:06. There is a double gas saving through reduced speed and also reduced distance. Additionally the shorter route is a much more interesting drive because the scenery is spectacular and the roads are more motorcycle friendly, not so boring and straight ahead as the major highways.

I don't think anything we do is going to stop oil prices from going up. People keep saying it's a supply and demand thing. Then how come the Saudi's increasing production twice in the last few months has done nothing to stop the rise in oil prices? Demand has increased but you don't need to be a mathematician to see that the rate of oil costs rising is not inline with the global demand increase. All we can do is worry about ourselves. I changed my driving habits not to try to affect oil prices, but to save ME money. Thinking that driving slower to save 2 or 3 miles per gallon is going to do anything to oil prices is crazy.

Maybe but it certainly can't hurt.

Demand IS causing the price to go up but.......speculation.......commodities traders.....the money changers......who add NOTHING to the economy but siphon OFF money into their own pockets....is causing a much BIGGER increase than supply/demand is.

This is the same mechanism that cause the big power fiasco in California (and other places) about 10 years ago. The "brokers" have now found another place they think they can make a "killing" .....and the collective "WE" are too stupid to put a stop to it.

These brokers are backed by a HUGE amount of money and, like usual, money talks.......and the little guy suffers so that the rich can get richer.

Phil, that can't be right. Max torque on my car is at 4500 RPM. Not sure what speed that would be, but about 2100 RPM gets me going right around 70MPH.

I'm sure you're correct about hitting a performance/efficiency curve where the increased efficiency outweighs the increased wind resistance. I just don't think it happens at that high of a speed.

Johnc
My Jaguar X-Type gets better millage at 65-68 MPH then when it is at 55. I have done the test and calculations on three different occasions and I get 27-28 MPG at 55 and 29-30 at 65-68. When doing 70 I get the same as 55. Temperature, humidity, tire pressure, wind all play a role and should be the same for all the test but that is just not possible.

What drives me nuts are the people that are either on the brakes or on the gas. I can't beleive people feel it is nessesary to race up to a red light. Add up the times in a trip you can coast up to a red light and your gonna save a lot of gas.

D-T, My old Regal was the same way. 70 MPH on a trip would get a steady 29 MPG, and the EPA rating was only 27 MPG for highway driving. But there, the tach was right around 2000 RPM @ 70 MPH, too.

It's something I always just accepted (mainly because it suited me). It was always a good excuse for riding my bikes through town @ 6000rpm in 1st gear

I had a trawl around the web looking for some proof (or otherwise), but didn't really find any. There's a bunch here (http://forums.mg-rover.org/archive/index.php/t-176991.html) arguing about the same topic.

I'm a little surprised that there isn't some sort of official or scientific test results posted somewhere. With today's cost of fuel, a transport company for example could save considerable costs by educating it's fleet drivers on the most efficient driving methods.

I would agree in principle with the concept that an engine near it's power peak should be more efficient than an engine laboring against a higher gear. What I think a scientific test will reveal is two opposing curves on a graph when evaluating fuel/mile vs power/speed and they will intersect at a point that indicates the highest efficiency at a certain speed. I would expect the efficiency to fall off after that, as the increasing wind resistance will take a higher and higher toll as speed increases. And then of course the curves will be different for each and every vehicle.

I have noticed that my bike seems to get better mileage at ~5500rpm(6th gear) at 75mph. If I drop or raise it by ~500rpm(<70or>80mph) I lose ~7%mpg. Have not really measured it at 5th gear or below though.

that sounds about right, figure most cars are set to get their best milage around 55 MPH. As you can imagine it does depend on teh car. There was a test not too long ago in fuel economy between a prius driving all out and a BMW M3 following it, the BMW did significantly better milage wise

Well on a happy note, there is this article promoting the good points about high gas prices.

http://www.time.com/time/specials/packages/article/0,28804,1...

Does anyone know for sure one way or the other, are these onboard computers that figures the gas mileage etc accurate, I wonder about mine sometimes if what it shows is correct or not, I have gotten upward of 26 mpg.out on the interstates.

You can try and compare it. Zero out your trip meter next time you fill up on gas. Do your driving, then, next time you fill up again, divide the miles you drove by the gallons it took to re-fill your tank.

I have found that they are not super accurate but within 1-2 mpg. I use it mainly to gauge my driving - also the info the onboard computer generates is used to give your estimated miles to empty.

This experience is off an 11,000 mile trp, a 5200 mile trip and several 3500 mile trips in the past 2 years.

I know Paul, but i am to lazy to figure that out, Really takes a lot dont it, LOL. just wondering if anyone had tried it.

I do record every fill up gallons/miles driven into an Excel file I wrote and it automatically computes my actual stats so I can compare against "trip computer" in car.
This shows me roughly when I need to pay attention to car if performance starts to slip.

So how does it come out ken. Higher, or lower than you actually figure.

I usually keep track too. It tells you when something is going wrong with the car and you can catch it early. Like if you typically get 35mpg then suddenly you start getting 25mpg. That sends up a 'time to get it checked out'. (like maybe a tune-up needs to be done or simple tires low on air or something major)

The actual is typically lower than the on-board computer by 1-2 mpg.

I guess i will run a couple of tanks and check and see what mine is acually doing. never done it on my new car, did on several others just to see how they did, but got out of the habit with the new one that has the trip computer, got my own curosity up on that one.
thanks ken and paul for the inputs.

http://fueleconomy.gov/ can help you track the gas mileage of your vehicle(s), and it has the option to share and compare results with other drivers of the same make and model.

I use it to compare which commute routes give me the best fuel efficiency.

Krieger