Speed vs Fuel Economy: Is Time Saved Worth The Added Cost?

Speed vs Fuel Economy: Is Time Saved Worth The Added Cost?

We all seem to be in a rush these days. Life's time demands seem to only increase, with the delicate balance of work, family, and recreation pressuring us to maximize every minute.

To quantify the impact a heavy right foot can have on your wallet, Consumer Reports recently conducted a seven-vehicle test comparing the fuel economy of each at speeds of 55, 65, and 75 mph. The results show the faster you drive, the more fuel you burn — no surprise there. But the most significant change in fuel economy comes from the most fuel-efficient vehicles we tested.

Miles Per Gallon At Given Speed

 

 

 

 

 

 

Make & Model

55 mph

65 mph

% Decrease

75 mph

% Decrease

Acura TSX

 

 

 

 

 

2.4-liter 4-cyl.

39.9

35.5

11.03%

30.7

23.06%

Honda Insight

 

 

 

 

 

1.3-liter 4-cyl.

51.9

44.8

13.68%

36.5

29.67%

Lexus RX 350

 

 

 

 

 

3.5-liter V6

30.9

27.4

11.33%

23

25.57%

Mercury Mountaineer

 

 

 

 

 

4.6-liter V8

23.8

21.2

10.92%

17.8

25.21%

Toyota Camry

 

 

 

 

 

2.5-liter 4-cyl.

40.3

34.9

13.40%

29.8

26.05%

Toyota RAV4

 

 

 

 

 

2.5-liter 4-cyl.

34.6

29.3

15.32%

25.9

25.14%

Toyota Yaris

 

 

 

 

 

1.5-liter 4-cyl.

42.5

37.9

10.82%

34

20.00%

 

 

 

 

 

 

Time to Complete A 100 Mile Trip

 

55 mph

65 mph

Time Saved

75 mph

Time Saved

Minutes

109

92

17

80

29

 

 

 

 

 

 

Fuel Cost ($2.50 Gallon) to Complete A 100 Mile Trip

 

 

 

 

 

 

Make & Model

55 mph

65 mph

% Increase

75 mph

% Increase

Acura TSX

 

 

 

 

 

2.4-liter 4-cyl.

$6.27

$7.04

12.39%

$8.14

29.97%

Honda Insight

 

 

 

 

 

1.3-liter 4-cyl.

$4.82

$5.58

15.85%

$6.85

42.19%

Lexus RX 350

 

 

 

 

 

3.5-liter V6

$8.09

$9.12

12.77%

$10.87

34.35%

Mercury Mountaineer

 

 

 

 

 

4.6-liter V8

$10.50

$11.79

12.26%

$14.04

33.71%

Toyota Camry

 

 

 

 

 

2.5-liter 4-cyl.

$6.20

$7.16

15.47%

$8.39

35.23%

Toyota RAV4

 

 

 

 

 

2.5-liter 4-cyl.

$7.23

$8.53

18.09%

$9.65

33.59%

Toyota Yaris

 

 

 

 

 

1.5-liter 4-cyl.

$5.88

$6.60

12.14%

$7.35

25.00%


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DexDiamondsDexDiamonds - 9/18/2009 11:48:49 AM
+6 Boost
...Yes ... it is


MSP6MSP6 - 9/18/2009 11:49:11 AM
+5 Boost
Definitely


Joe_LimonJoe_Limon - 9/18/2009 12:02:11 PM
+1 Boost
Depends how much your time is worth. If you are unemployed then no.


Joe_LimonJoe_Limon - 9/18/2009 12:17:41 PM
0 Boost
How about a tax on middle eastern oil? :P There is lots of it on this continent, it's just more expensive to get at.


Joe_LimonJoe_Limon - 9/18/2009 2:11:58 PM
+5 Boost
If that were true, Europe's traditionally high gas prices would mean that they should already be leading the "green" revolution.


Joe_LimonJoe_Limon - 9/18/2009 6:51:32 PM
+2 Boost
No, there are numerous companies in North America that are investing in "green" technologies. Look at Ballard towards the numerous advances they have made towards hydrogen fuel cell technology, The numerous windmill farms owned by oil companies that litter the windier parts of the country. As well as the few solar powered breakthroughs down in the southern states. Hell, even the automotive industry has Tesla located in North America. These companies are already here and are doing just as well as your aforementioned European counterparts.


SpicyMikeySpicyMikey - 9/18/2009 1:25:31 PM
+1 Boost
^^ but they still would get better gas mileage at 55. It's a matter of physics not engine tuning. The faster you go, the more resistance you have from the air, moving parts, road friction, etc. Plus the faster you go through the air the more turbulance and lift that is created requiring more downforce from body design to counter the affect thus creating more drag. You can't tune away Newton's laws of motion.


Joe_LimonJoe_Limon - 9/18/2009 10:42:22 PM
+2 Boost
It all depends on the gearing, if a car is geared for 2000rpm at 65mph, it may only take 10% throttle, but if you drop it down to 55mph, the drop in rpm will lead to a drop in torque and may make 20% throttle necessary, thus an increased fuel consumption.


SpicyMikeySpicyMikey - 9/20/2009 9:34:25 AM
+1 Boost
True, but once again, you can't tune away the laws of physics. It takes more energy to move an object faster, period. You can tune it to be biased towards speed or torque, you can even keep adding gears to reduce the rpm's at higher speeds, but F=MA always wins. Not suggesting we all drive 55, just saying there IS an energy penalty.


HSCenterconsoleHSCenterconsole - 9/18/2009 1:05:05 PM
+5 Boost
Yes, I can afford the gas and my life is too busy to be wasting time driving at 55mph.


ForeignerForeigner - 9/18/2009 1:15:44 PM
+4 Boost
Agreed. Same here.


FanboyOfTheTruthFanboyOfTheTruth - 9/18/2009 4:50:09 PM
+3 Boost
...unless you turn off the engine and/or put the gear in neutral like any normal driver would do, of course.


BobWBobW - 9/18/2009 1:59:54 PM
+3 Boost
You need to convert the minutes saved into a percentage to make a direct comparison with the other figures. At 65 mph it takes 15.6% less time and at 75 mph 26.6% less. So in every case except the Insight at 75 mph you have saved more time as a percentage of the total then you've reduced your mileage. However in out-of-pocket expense, you're ahead on time saved at 65 mph for all but the Insight and RAV4, but at 75 mph it costs more then the time saved (again as a percentage of the total) in every car but the Yaris.
To me, it's worth it to spend the extra $$ to drive faster and get there quicker--especially if it's a long trip. As for my time--I'm retired so the value of my time is rarely in the equation. I just like to go faster.
BW


achilesachiles - 9/18/2009 3:34:09 PM
+1 Boost
You would also need to add the fact that at 75 you will have some stone damage on your bumper, not to mention bugs so will need to add a car wash, some of you may have a car bra but for a good one you will have to spend at least $100, not to mention the extra stress on all moving parts.


Joe_LimonJoe_Limon - 9/18/2009 4:08:21 PM
+1 Boost
do you drive?


MSP6MSP6 - 9/18/2009 5:47:58 PM
+1 Boost
You can wash it yourself... or leave it dirty


truckmantruckman - 9/18/2009 6:06:55 PM
+1 Boost
I don't trust there numbers, they may be correct? The epa is out to lunch with there numbers, I would like to see real numbers, I recently did a trip with my 2007 civic and drove 1400.km HWY and averaged 6.5L/100km a month later I drove the same trip with two more people in a 2004 Grand Am and averaged 7.7L/100km averaging the same speed, what gives? The Honda wasn't that much better and it is supposed to be so green and the Grand Am is supposed to be a gas guzzler? As far as I am concerned they were almost the same, except the Grandam was bigger.And I would drive faster for saving my time.


LexusKindaGuy12LexusKindaGuy12 - 9/18/2009 10:18:11 PM
+1 Boost
If time is money, then it all comes out equal in the end


WorldofLuxuryWorldofLuxury - 9/19/2009 2:26:41 AM
+1 Boost
It's a different story for cars with bigger engines - just a slight left skew in the stats. lol


JanizaryJanizary - 9/21/2009 8:10:22 PM
+1 Boost
Sorry to take a hard left, but this title of this article made me think about the sod in the blue Prius that passes me almost every morning in a slow-down-for-construction zone. Speed limit drops from 65mph to 45mpg, but the fellow in the Prius zips along passing everyone going at or above the normally-posted speed limit of 65mph.

Two times in two weeks I've seen him pulled over by LVMPD motorcycle cops. I'm guessing that going faster is saving him a whole lot the last few weeks ;)

(No, I'm not picking on Prius drivers. I just find it ironic that the speeding driver is a Prius driver)
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