Not Logged In Log In   Sign Up   Points Leaders
Follow Us    9:31 AM

Message Forum - Read Message

Category: Fuel Economy > Topics Add to favorite topics   Post new topicPost New Topic
Author Topic: Speeding reduces gas mileage per gallon. Back to Topics
tazdriver

Champion Author
Huntsville

Posts:4,913
Points:1,951,595
Joined:Jan 2007
Message Posted: Dec 31, 2007 10:38:27 AM

Must be some state of denial (not talking about some place in Egypt) when we speed and at the same time complain about high gas prices. It has been shown time and time again that slowing down could single handedly cut in half the amount of gasoline we consume. So why do we speed?
REPLIES (newest first) Post a Reply
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jul 13, 2014 9:40:32 AM

It should by design. Like buying a Big Dog and getting Big Dog results!
Profile Pic
redfish67
Champion Author Dallas

Posts:1,173
Points:233,525
Joined:Dec 2013
Message Posted: Jul 13, 2014 9:31:15 AM

it's a no brainer
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jul 13, 2014 9:29:44 AM

Valandingham: The self driving test you refer to, rather several and then that comparison, for finding a better Idea/way to save fuel has merit.

I have done on occasion a few practices with my econo ride, but the real results that counts is a combination of a lot of improved habits/and concentration when driving. That doesn't always happen on a regular basis by the average driver.

I find staying aware of Engine run time V/S destination mileage, each time, per each startup/start off and affected by traffic often puts a clamp on the fuel costs, and increasing them. Add bad driving habits to that mix leaves the results messed at times.

I call the Idea that you mentioned to save fuel no pun intended, I call it the Elephant/Horse Engine game which is effected by time intervals of the engine's energy use.

The elephant being the E..torque limits and the horse being the engines quick power ability, which builds at the upper rpm range, with both using up fuel to please the driver choice commands driving the vehicle.

Every day driving requires many encounters with varied conditions for saving a bit of fuel. Most know elephants are powerful lugging beasts but somewhat slow energy and a horse can deliver moderate power with more speed. The ICE gas engine by comparison has both qualities with out feeding them fuel when idle.

Engines deliver harmony power if the driver learns what correct practices are needed for that average choice of use is overall the time interval of travel with>>> the Engine on till >>> engine turns off, satisfied Happy Driver(very good choices) $$ saved at the next refuel! Testing is a good Idea.... HABDay! (Better)!....
Profile Pic
gougedQC
Champion Author Montreal

Posts:5,635
Points:76,685
Joined:Apr 2008
Message Posted: Jul 13, 2014 9:06:28 AM

no housckster- it is not untrue- along the lines of what- dontuknow= posted, different vehicles have different optimum speed-consumption rates.

I would venture a Porsche gets better mileage at 75 than 55 whereas a ford 350 pickup probably is the opposite

BTW- top gear tested a Prius and a big BMW around a race track..with the prius leading as fast as it could and the dimmer M3 following... after one gallon (imp) the prius ran out and the Bimmer kept going

now reduce that speed to 55 (snore) and the prious would probably win.. but the point is proven
Profile Pic
Valandingham
Champion Author Washington

Posts:9,027
Points:1,848,595
Joined:Mar 2005
Message Posted: Jul 12, 2014 6:22:39 PM

The thing that I have found is that if you use MORE fuel traveling SLOWER to keep the slower speed taking more time to get somewhere than if you were traveling at a much HIGHER SPEED taking Less Time to get somewhere and using LESS FUEL.
The same goes if you take your time to get up to speed from a stop you use MORE FUEL over a LONGER DISTANCE and TIME than if you Put you foot down and get up to speed on a Shorter distance and time which uses LESS FUEL.

The best way to test this out is to take a long road trip at a constant speed limit of 60, 65 or 70 depending on the U.S. state or Canadian Providence your in with Cruise Control being used over the weekend. And try the same thing without Cruise Control in the Weekly Grind of Rush Hour Traffic and see how much MORE FUEL you use.
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jun 30, 2014 10:12:32 PM

I think about motorized vehicles and their engine fuel/power efforts as similar to ones Human energy exerted when riding a multispeed bicycle.If you have ever ridden a bike that has gearing changes often you often pick one out of 5 speeds to cruise at. You will find a top gear that is right in pedal speed, then pressure force exerted for whatever resistive forces encountered, and that may change as you ride.

The same is true with automotive designs, Engineers pick an optimum high gear for most average midrange travel speeds when engine torque is near it's peak but with a percentage of reserve for an over-drive top cruise gearing when conditions permit.

Level terrain, moderate load, only slight towing, minimum highway speed, all pertain to the engines best breathing/torque/harmony = best fuel economy with a slight reserve of pulling a taller final gear ratio like over-drive.

My opinion is often there is possibly better mileage with less engine effort thus fuel savings is determined by The vehicles ECM tested levels when designed, for each type vehicle/application.(averaging road conditions)per drivetrain/final top gearing matched to each engine's energy power.

You decide what matches your energy levels of Human power when riding the multi-speed bicycle by selecting the proper gear, this affects your average travel speed while pedaling. Sometimes you use your reserve and sweat a little, breath harder, coast to recover, and how is your tank doing? Food/Drink Tank! What gear choice? for cruising Harmony("Sweet Spot Speed") !!
Profile Pic
luvmyrv
Veteran Author Winnipeg

Posts:472
Points:325,555
Joined:Dec 2012
Message Posted: Jun 30, 2014 4:49:04 PM

You could say the same thing about many things in life....smoking increases risk of cancer, why do people do it? Too much take out and fast food can lead to obesity, why do people continue to supersize their order?
Profile Pic
PhilnTX
All-Star Author Dallas

Posts:755
Points:778,140
Joined:Sep 2011
Message Posted: Jun 30, 2014 4:35:29 PM

OK
Profile Pic
eyegotgas2
Champion Author British Columbia

Posts:3,519
Points:707,880
Joined:Sep 2011
Message Posted: Jun 30, 2014 3:02:50 PM

Everybody knows it but we do it to save on time generally or to some it has become a habit
Profile Pic
Houckster
Champion Author Atlanta

Posts:11,007
Points:763,505
Joined:Sep 2003
Message Posted: Jun 30, 2014 1:20:56 PM

AWING1 writes: Yes, that's right, but if you drive at constant high speed (eg. 75 mph etc) on the highway, it would be better than city driving (because of stopping and going).
______
You really can't compare city and highway driving. It's like apples and oranges.

When the car reaches top gear or OD, that's where the question really is. Some people will contend, for example, that by driving 65 as opposed to 55, they get better mileage. This is untrue. As vehicle speed increases so does wind resistance and vehicle RPM. One possible exception might be for a vehicle with cylinder deactivation but when the key variables are held constant except for speed, 55 MPH will yield better mileage than 65 MPH.

Profile Pic
GLM4205
Champion Author Toledo

Posts:5,984
Points:1,209,440
Joined:Dec 2010
Message Posted: Jun 30, 2014 12:49:24 PM

Sure it does.
Profile Pic
twt
Champion Author Virginia Beach

Posts:12,195
Points:1,446,310
Joined:Mar 2005
Message Posted: Jun 28, 2014 3:04:00 AM

DUH, the faster your engine is running, the more fuel is consumed.
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jun 27, 2014 10:09:56 PM

Weaslespit is right about the 10 mph cruising speed being a dud for decent mileage.

Vehicles at that speed are turning great amounts of rpm in relation to ground travel in distance, low rpms maybe but lots, great amounts!

Also a vehicle would not be able to correctly cool itself, coolant fans would run heavily then causing large amounts of alternator load (wasting fuel)that way.

Then the transmission also would stay in a 1st. or 2nd. gearing mode with more heat build-up, so Extreme Pokey would be risky, waste fuel, cause mechanical harm to the vehicle, and look really dumb to be on the roadway if no running in a crippled condition(Flashers in use)constantly.

My good range is 60-67 MPH. for economy, and that varies with road conditions/atmosphere/ amount of accessories in use.
Profile Pic
Weaslespit
Champion Author Cincinnati

Posts:14,780
Points:506,665
Joined:Sep 2008
Message Posted: Jun 25, 2014 9:52:07 AM

"Amen, NO vehicle gets better mpg as mph increases;"

This statement is untrue. You do not get better gas mileage cruising at 10 mph than at 65 mph... It is all about the gearing - you get the best gas mileage in your highest gear. Where in the curve maximum mpg is attained relative to speed/power is dependent on the vehicle.
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jun 25, 2014 9:33:51 AM

It surely must be hard for some to understand that vehicles are designed to use more fuel when their engines are required to work harder at higher RPMs or when coupled to a too tall gearing ratio which depends on the terrain traveled, extra head wind, stop/go inertia forces, extra weight loads, other resistive forces.

Some drivers learn what their vehicle's Harmony (Sweet Spot Speed)is and then go with that, others don't care even though they drive somewhat of an economy vehicle they often push it to their $... affordable limits/habits.

Some are Dense to saving fuel(don't know just what to do)to improve their mileage, and often get the Horn blasts heard daily directed toward them, Really!?? Blasts are different than toots HMmmmm....
Profile Pic
herbiepopnecker
Champion Author British Columbia

Posts:15,628
Points:2,939,080
Joined:Sep 2005
Message Posted: Jun 24, 2014 10:56:13 PM

Because of weather conditions I had to drive home at 80kph (50) instead of my regular 110kph (70).
Next morning I fired up the car and saw the gas gauge ant thought 'there's way too much gas left after that trip!"
Amazing the difference speed makes.
Profile Pic
kxy4fw
Champion Author Denver

Posts:1,252
Points:283,330
Joined:Nov 2011
Message Posted: Jun 24, 2014 1:26:42 PM

???
Profile Pic
the1roadhog
Champion Author Atlanta

Posts:11,520
Points:2,499,210
Joined:Jun 2007
Message Posted: Jun 24, 2014 8:06:37 AM

No kidding????
Profile Pic
Awing1
All-Star Author Ontario

Posts:770
Points:164,785
Joined:Aug 2013
Message Posted: Jun 24, 2014 7:56:07 AM

Yes, that's right, but if you drive at constant high speed (eg. 75 mph etc) on the highway, it would be better than city driving (because of stopping and going).
Profile Pic
luxette007
Rookie Author Long Island

Posts:8
Points:4,425
Joined:Jun 2014
Message Posted: Jun 24, 2014 6:23:45 AM

Simply enough: impatience, time-constraints, people wanting and needing to get to where they're going on time or early. Plenty of arguments to be made for making extra time before getting on the road so one can drive slowly and allow for traffic (easier said than done, usually) but people are only concerned about gas when a) they're running low and/or b) they aren't able to get much of it. En route to work, an appointment, a function, or even just home for the day is rarely where you think "drive slow, save gas".
Profile Pic
twt
Champion Author Virginia Beach

Posts:12,195
Points:1,446,310
Joined:Mar 2005
Message Posted: Jun 24, 2014 5:38:53 AM

We speed, because we're stupid.
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jun 23, 2014 8:36:42 PM

They need to call the Go pedal the "Slurp Pedal" and the brake pedal the Has Been pedal....
Profile Pic
texaskellys
Rookie Author Houston

Posts:11
Points:53,120
Joined:Feb 2008
Message Posted: Jun 22, 2014 1:05:06 PM

Amen, NO vehicle gets better mpg as mph increases; #1 factor in mpg is still wind resistance, even in modern aerodynamic design (point taken in the comment about the Corvette).

Why we speed is an altogether different question, which, unfortunately like why we still have famine in the middle of abundance, poverty with so much wealth, watt and a host of other issues. Too many of is are concerned with "me" instead of "we."
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jun 20, 2014 2:25:46 AM

I believe its suppose to, things being normal. Its the excitement that drops any concern and the valuable time gained back to ones person use. There are some that don't waste a moment of time, I get it!.......
Profile Pic
thebrohta167
Champion Author New Jersey

Posts:2,090
Points:364,600
Joined:Nov 2010
Message Posted: Jun 19, 2014 1:58:07 PM

ok
Profile Pic
StArrow68
Champion Author Oakland

Posts:5,456
Points:1,812,855
Joined:Apr 2003
Message Posted: Jun 19, 2014 12:16:24 PM

Some seem to confuse speeding with speed. Speed is what gets you to your destination in a reasonable amount of time and if you want to spend more time and less on fuel you can drive below the limits. Speeding is presumably exceeding those limits and risks getting the attention of the law and costing you much more than the slight amount of additional fuel you consume.
Profile Pic
lostsoul
Sophomore Author Los Angeles

Posts:241
Points:282,070
Joined:Jun 2012
Message Posted: Jun 19, 2014 11:41:18 AM

without a doubt
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jun 19, 2014 7:46:31 AM

Yes because your vehicle is designed to produce more power when you the driver pushes the go-pedal farther down. Actually you turn the go fast fuel faucet system to a more opened position to create that extra engine energy.

There is always a harmony speed where the engine, aerodynamics, wind, rolling friction, gearing comes into balance for a cruising travel speed
that is the most economical, and that speed varies among vehicles and road conditions, Drivers habits mostly have the greater affect on mileage.....
Profile Pic
cv
Champion Author Raleigh

Posts:17,387
Points:3,724,680
Joined:Oct 2003
Message Posted: Jun 19, 2014 5:16:34 AM

Yes, my ideal speed on the Interstate for maximum mileage is 65mph, but that is much slower that others drive.
Profile Pic
hooky
Champion Author Michigan

Posts:28,181
Points:2,871,970
Joined:Sep 2005
Message Posted: Jun 17, 2014 8:52:43 AM

Endless drool!
Profile Pic
Awing1
All-Star Author Ontario

Posts:770
Points:164,785
Joined:Aug 2013
Message Posted: Jun 17, 2014 7:59:33 AM

Speeding up takes more gas, but if you driving at the same high speed consistently, it would be better than slow and stop. That's why highway mpg is better than city driving. Conclusively, you can not say that slow driving saves gas always due to other factors.

[Edited by: Awing1 at 6/17/2014 8:00:20 AM EST]
Profile Pic
poetdog73
Champion Author Toledo

Posts:1,308
Points:957,230
Joined:Aug 2008
Message Posted: Jun 17, 2014 2:19:15 AM

bull!
Profile Pic
counterattack
Veteran Author Los Angeles

Posts:270
Points:95,220
Joined:Nov 2013
Message Posted: Jun 16, 2014 11:04:05 PM

Speed because it is fun. I enjoy hearing my engine rev up to redline. Not all the time but at least once a week is good.
Profile Pic
Mikeyl
Champion Author Cleveland

Posts:8,046
Points:1,629,130
Joined:Aug 2004
Message Posted: Jun 16, 2014 5:43:56 PM

Use your cruise control... set it and forget it.
Profile Pic
dassfg
Champion Author Fort Worth

Posts:1,966
Points:936,520
Joined:Mar 2011
Message Posted: Jun 14, 2014 7:50:51 AM

Speeding up then slowing down then speeding up reduces fuel mpg -- drive a consistent speed
Profile Pic
twt
Champion Author Virginia Beach

Posts:12,195
Points:1,446,310
Joined:Mar 2005
Message Posted: Jun 14, 2014 4:32:09 AM

I totally agree. Higher speed, uses more gas.
Profile Pic
eptraveler
Rookie Author El Paso

Posts:37
Points:15,350
Joined:Mar 2011
Message Posted: Jun 13, 2014 8:55:21 PM

All I know is that when I put the old cruise control on 65, I get several more miles per gallon (34 or so) than when I run the 80 MPH speed limit in West Texas (around 30.) So I get there 20 minutes earlier. Who cares? (Yes, I know that 15 mph over 6 hours = 90 miles closer at 80 than 65 or roughly 1:25 earlier arrival. Don't care. I'm not racing you.) The savings in money AND the energy savings is worth it for me. Plus, chances are real good that I'm going to pass you at the gas station. I'll wave as I drive by.

Believe me, I have certainly done my share of hot-rodding. I think high prices went a long way in slowing me down.
Profile Pic
Ready2Cycle
Veteran Author Wichita

Posts:297
Points:290,725
Joined:Aug 2012
Message Posted: Jun 13, 2014 9:40:58 AM

MPG's go up you slow down.In a hybrid, there's a sweet spot around 39 mph.
Profile Pic
Skyjunky
All-Star Author Portland

Posts:524
Points:95,695
Joined:Oct 2004
Message Posted: Jun 13, 2014 7:53:34 AM

MPG's go down after about 55 mph
Profile Pic
hoopitup2000
Champion Author Virginia

Posts:1,123
Points:316,025
Joined:Jul 2013
Message Posted: Jun 13, 2014 6:54:12 AM

Sure does!!
Profile Pic
StArrow68
Champion Author Oakland

Posts:5,456
Points:1,812,855
Joined:Apr 2003
Message Posted: Jun 13, 2014 5:33:17 AM

Aside from the snide comments, you might be overlooking that you don't do 60 or 70 in the city. Once a vehicle is in top gear, not as simple as that use to be prior to variable or 7 to 10 speed transmissions, and wind resistance starts to impact how many rpm are required to maintain speed, the mpg will generally decline as you push on the accelerator more.
Even the Corvette gets hit by wind. So, I can do 69 mph at 1500 rpm and red line is 6000 rpm or four times higher. Why is top end 172mph and not 276? Might just have something to do with wind resistance and pushing that wind doesn't improve your mpg.
Claiming that you get better mpg at 70 vs 60, isn't the same as proving it.
Profile Pic
scottmccarrick
Champion Author Boston

Posts:2,930
Points:593,375
Joined:Dec 2012
Message Posted: Jun 13, 2014 4:57:50 AM

how does that work? All stats prove otherwise. Even the sticker of a new car show 18-25 city and 25 and up for highway. Now understand what im typing. You drive SLOWER in the city and FASTER on the highway. by your stupid statement these figures should be reversed. I get youre a sheep, BUT dont be an idiot
Profile Pic
mnrick041
Champion Author Twin Cities

Posts:17,094
Points:1,827,305
Joined:Jun 2009
Message Posted: Jun 11, 2014 9:23:04 PM

Generally the faster you go the worse your MPG will be but the speed at which you will get optimal gas mileage will vary from car to car.
Profile Pic
stonejd
Champion Author Illinois

Posts:1,678
Points:608,625
Joined:Feb 2012
Message Posted: Jun 9, 2014 6:33:51 AM

I have gotten better mpg while doing 70 vice 60 in my camaro
Profile Pic
scottmccarrick
Champion Author Boston

Posts:2,930
Points:593,375
Joined:Dec 2012
Message Posted: Jun 9, 2014 6:13:13 AM

So i drive 67-72 mph and i get 33 or so mpg
then i drive 55 and get 28 or so mpg
Show me how i cut it in half?
You [The OP] are a sheep and an idiot if you believe ANYTHING the gubbermant tells you

[Edited by: scottmccarrick at 6/9/2014 6:13:42 AM EST]
Profile Pic
WilhamClouse
Champion Author Calgary

Posts:1,976
Points:420,775
Joined:Jun 2013
Message Posted: Jun 8, 2014 8:20:49 PM

Don't care. Speed limits are too low.
Profile Pic
Madridjoe
Veteran Author Lancaster

Posts:361
Points:222,920
Joined:Jun 2007
Message Posted: Jun 7, 2014 10:38:01 PM

everyone is in a hurry?
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,260
Points:56,585
Joined:Aug 2009
Message Posted: Jun 7, 2014 8:56:42 PM

It really should or something is wrong. If your vehicle doesn't use more fuel when you hammer the go pedal down, it's not running normal, their designed to use more fuel during RUSH HOUR" or when the driver gets heavy footed!
Profile Pic
contiki
Champion Author Ontario

Posts:24,753
Points:969,965
Joined:Sep 2008
Message Posted: Jun 7, 2014 8:37:25 AM

For sure............
Profile Pic
contiki
Champion Author Ontario

Posts:24,753
Points:969,965
Joined:Sep 2008
Message Posted: Jun 6, 2014 6:55:03 AM

yes...............
Post a reply Back to Topics