does driving slower really save you money?

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xanis

Lifer
Sep 11, 2005
17,571
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Originally posted by: Anubis
Originally posted by: mariok2006
Where the hell does traffic go 80mph in a 55mph zone? l.

eyerywhere in this country

Pretty much. Have you ever driven on I-95 anywhere on the east coast?
 

xanis

Lifer
Sep 11, 2005
17,571
8
0
Originally posted by: Anubis
Originally posted by: Xanis
Originally posted by: Anubis
Originally posted by: mariok2006
Where the hell does traffic go 80mph in a 55mph zone? l.

eyerywhere in this country

Pretty much. Have you ever driven on I-95 anywhere on the east coast?

ugh I-95 is a shithole, especially between CT and DC

You're telling me. I live in PA, home to some of the shittiest roads in the country. And in the interest of keeping this somewhat on-topic, the general rule is "95 on 95".
 

Anubis

No Lifer
Aug 31, 2001
78,712
427
126
tbqhwy.com
Originally posted by: Xanis
Originally posted by: Anubis
Originally posted by: Xanis
Originally posted by: Anubis
Originally posted by: mariok2006
Where the hell does traffic go 80mph in a 55mph zone? l.

eyerywhere in this country

Pretty much. Have you ever driven on I-95 anywhere on the east coast?

ugh I-95 is a shithole, especially between CT and DC

You're telling me. I live in PA, home to some of the shittiest roads in the country. And in the interest of keeping this somewhat on-topic, the general rule is "95 on 95".

yea the limit in parts of the south,.. SC, GA, is 70, when i drove down there to see my brother the majority of traffic was doing 90-100
 

nakedfrog

No Lifer
Apr 3, 2001
63,170
19,507
136
Originally posted by: Chiropteran
Originally posted by: AMCRambler
I like watching the people that are in a huge hurry go from red light to red light like a raped ape. Meanwhile I drive normally and get there a few minutes later, lol. I don't drive 5 under the limit to save gas though. My personal time is worth more to me than a few nickels at the pump every fill up.

I like watching people that drive to work on local roads instead of using a proper highway. I never suggested speeding from light to light, that is silly. Why would anyone choose to drive to work on a road full of stoplights anyway?

It's funny you should bring that up. When I first started here, I took the freeway almost the entire way. Now I've switched to only using it until I can get onto one of those local roads full of (timed) stoplights, and it takes the same amount of time, +/- a minute or two depending on the day.
 

xanis

Lifer
Sep 11, 2005
17,571
8
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Originally posted by: nakedfrog
Originally posted by: Chiropteran
Originally posted by: AMCRambler
I like watching the people that are in a huge hurry go from red light to red light like a raped ape. Meanwhile I drive normally and get there a few minutes later, lol. I don't drive 5 under the limit to save gas though. My personal time is worth more to me than a few nickels at the pump every fill up.

I like watching people that drive to work on local roads instead of using a proper highway. I never suggested speeding from light to light, that is silly. Why would anyone choose to drive to work on a road full of stoplights anyway?

It's funny you should bring that up. When I first started here, I took the freeway almost the entire way. Now I've switched to only using it until I can get onto one of those local roads full of (timed) stoplights, and it takes the same amount of time, +/- a minute or two depending on the day.

Exactly. I only live ~8 miles from work, so to get to the highway, drive on it, and get off near work would take a lot more time than taking a local roads.
 

Chiropteran

Diamond Member
Nov 14, 2003
9,811
110
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Originally posted by: dullard
(1) Time is only money if you would have worked during that wasted time. If your choice is (a) drive 14 minutes more vs (b) work 14 minutes more at an hourly paid job, then your math is important. If your choice is (a) drive 14 minutes more vs (b) waste 14 minutes looking at yourself in the mirror in the morning, then your math is wrong. In this latter example, you get paid the same each year regardless of the option you choose - time wasn't money. Yes, you can put an intangible value on that wasted time, but it often is NOT the value of what you are paid at your current job.

You are right. Your time might be worth *more* to you than what your job pays, after all your job also gives you benefits such as experience, medical benefits, paid vacation, etc. Maybe by coming in to work 5 minutes early every day your boss takes notice and ends up giving you a promotion. Maybe by using those extra minutes each morning to eat a healthy breakfast instead of stopping for fast food you can lead a healthier life and live 10 years longer than you would otherwise.

While there isn't any definitive value of time, I'm just pointing out that even based on a fairly low value of $20/hr driving slow to save gas is a net loss. If you are telling me that your time is worth less than that, that's fine. Whatever value you put on it and works for you is cool.

For me, the value of my time is directly proportional to my enjoyment of what I'm doing with it. If I'm doing something I like, such as hanging out with friends, gaming, or taking a nice walk, the enjoyment I get out of the activity outweighs the loss of time, so I don't really value that lost time as heavily. However if I'm doing an activity I dislike doing, such as driving in the slow lane and watching cars pass me, I'm going to count the value of that time very highly.

Even then I'll admit there are exceptions. Maybe I just got a new CD and I want to listen to it a little longer on the way to work, I might be perfectly happy to drive slower. I see no problem with driving slower for other reasons. I just find it stupid to drive slowly purely for the purpose of saving money on gas.

Originally posted by: dullard
(2) In some cases (free flowing highway/interstate), driving faster gets you there sooner. In some cases (timed stop lights, overcrowded roads) driving faster does NOT get you there sooner. Please don't assume that your case of having more free time applies to us. It may or it may not.

I'm not "assuming" anything.

1- I specified HIGHWAY miles. Obviously people aren't going to be driving 80mph in the city. Use some basic common sense.

2- If your speed is limited by traffic, this whole discussion is redundant. Obviously, it's only a question if you should drive faster when driving faster is actually an option- there is no reason to consider driving faster when driving faster is impossible due to traffic conditions.

However. If your speed is limited by traffic, it's a net of zero change. If you are a conservative driver or a go-with-the-flow speeder, either way you will be driving 40mph when traffic is backed up and moving at 40mph, so your gas consumed and time wasted will be identical. Statistically, such situations can be ignored because they have a net affect of zero change.


Originally posted by: dullard
Driving smart saves money without necesarilly losing time.

Again, I'm *only* talking about deliberately driving below the speed limit and flow of traffic. General "smart driving" tactics are not even being compared. You can still drive smart while driving with the flow of traffic.
 

Vic

Elite Member
Jun 12, 2001
50,422
14,337
136
Fast or slow, I get the same gas mileage. The bigger issues are city or highway, stuck in traffic, etc. That's when you'll notice the biggest differences in gas mileage.
The notion that slow acceleration and bogging gears will save gas is complete bunk, except when compare to pedal-to-the-metal driving. Gas engines are most efficient within a particular operating range. I describe it as when you can feel the engine "float." Find that range for your car and you'll be able to drive normally and get good gas mileage at the same time.
 

nageov3t

Lifer
Feb 18, 2004
42,808
83
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50 mph vs 80 mph seems like a weird comparison.

maybe they mean 5 miles under the average speed versus 5+ miles over?
 

Imported

Lifer
Sep 2, 2000
14,679
23
81
My commute is about 30 miles.. 25 or so being on the highway. I used to set the cruise to 80.. now I set it to 70. Its maybe another 5 minutes of driving, but I've been able to stretch filling up every 330miles to about every 370miles now. I also get paid the same, no matter if I come in 15 minutes early ot 15 minutes late.
 

Chiropteran

Diamond Member
Nov 14, 2003
9,811
110
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Originally posted by: loki8481
50 mph vs 80 mph seems like a weird comparison.

maybe they mean 5 miles under the average speed versus 5+ miles over?

I really can't believe there would even be a measurable difference between driving 10mph +/- either way. I mean even when I drive at "80mph" I know my actual speed is going to vary from 75-81mph give or take.

I based the numbers off what I have heard people say- they drive 5 mph below the limit to save gas. While I know the average speed in this area is about 20 mph above the limit. So that is where my weird comparison came from.
 

Chiropteran

Diamond Member
Nov 14, 2003
9,811
110
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Originally posted by: Imported
My commute is about 30 miles.. 25 or so being on the highway. I used to set the cruise to 80.. now I set it to 70. Its maybe another 5 minutes of driving, but I've been able to stretch filling up every 330miles to about every 370miles now. I also get paid the same, no matter if I come in 15 minutes early ot 15 minutes late.

Instead of leaving 15 minutes late and driving 70 you could leave 20 minutes late and drive 80 ;)

You are saving $1/day for 10 minutes of your time. $21/month for 3.5 hours. Is your time really so worthless to yourself?

I'd happily pay $21 to get an extra 3 and half hours to do whatever I want with.
 

Xavier434

Lifer
Oct 14, 2002
10,373
1
0
Originally posted by: Aikouka
Originally posted by: Xavier434
I think what will save you more money is to decrease your acceleration rather than your velocity. It's all about the RPMs anyways. Also, allowing your vehicle to coast longer while approaching red lights is good too.

Wind resistance is a bitch at 70+ :p.

How much more gas is used when going 75 mph as opposed to 65 mph due to wind resistance on average though? I realize this depends on a few factors, but I think the point is still sound. I cannot imagine it being that much especially compared to the amount one saves by pacing their acceleration combined with more coasting.




Originally posted by: Chiropteran
Originally posted by: Imported
My commute is about 30 miles.. 25 or so being on the highway. I used to set the cruise to 80.. now I set it to 70. Its maybe another 5 minutes of driving, but I've been able to stretch filling up every 330miles to about every 370miles now. I also get paid the same, no matter if I come in 15 minutes early ot 15 minutes late.

Instead of leaving 15 minutes late and driving 70 you could leave 20 minutes late and drive 80 ;)

You are saving $1/day for 10 minutes of your time. $21/month for 3.5 hours. Is your time really so worthless to yourself?

I'd happily pay $21 to get an extra 3 and half hours to do whatever I want with.

The only problem with that logic is that you do not get 3.5 hours in a lumped sum to do whatever you want. You are forced to spread it out in 5 min increments twice a day. That's pretty worthless.
 

randay

Lifer
May 30, 2006
11,018
216
106
i enjoy driving so if my drive is a few minutes longer then it would be on "average" i couldnt care less. and if i save myself a few bucks in the process great!
 

finite automaton

Golden Member
Apr 30, 2008
1,226
0
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Originally posted by: Xavier434
Originally posted by: Aikouka
Originally posted by: Xavier434
I think what will save you more money is to decrease your acceleration rather than your velocity. It's all about the RPMs anyways. Also, allowing your vehicle to coast longer while approaching red lights is good too.

Wind resistance is a bitch at 70+ :p.

How much more gas is used when going 75 mph as opposed to 65 mph due to wind resistance on average though? I realize this depends on a few factors, but I think the point is still sound. I cannot imagine it being that much especially compared to the amount one saves by pacing their acceleration combined with more coasting.

It depends on how wind resistant your vehicle is, but I get a ~12% loss in a lifted Jeep Liberty just going from 60 to 65.
 

Xavier434

Lifer
Oct 14, 2002
10,373
1
0
Originally posted by: finite automaton
Originally posted by: Xavier434
How much more gas is used when going 75 mph as opposed to 65 mph due to wind resistance on average though? I realize this depends on a few factors, but I think the point is still sound. I cannot imagine it being that much especially compared to the amount one saves by pacing their acceleration combined with more coasting.

It depends on how wind resistant your vehicle is, but I get a ~12% loss in a lifted Jeep Liberty just going from 60 to 65.

I guess my car's loss is a lot less because I did try lowering my speed by 10 mph once starting after I filled my tank. I didn't notice any difference at all. I still had to fill her back up after driving it for the same number of days.
 

overst33r

Diamond Member
Oct 3, 2004
5,761
12
81
Originally posted by: Xavier434

How much more gas is used when going 75 mph as opposed to 65 mph due to wind resistance on average though? I realize this depends on a few factors, but I think the point is still sound. I cannot imagine it being that much especially compared to the amount one saves by pacing their acceleration combined with more coasting.

Wind resistance increases with the square of velocity. So if you increase your speed by 15%, you are increasing wind resistance by 33%.
 

overst33r

Diamond Member
Oct 3, 2004
5,761
12
81
Originally posted by: Xavier434
Originally posted by: finite automaton
Originally posted by: Xavier434
How much more gas is used when going 75 mph as opposed to 65 mph due to wind resistance on average though? I realize this depends on a few factors, but I think the point is still sound. I cannot imagine it being that much especially compared to the amount one saves by pacing their acceleration combined with more coasting.

It depends on how wind resistant your vehicle is, but I get a ~12% loss in a lifted Jeep Liberty just going from 60 to 65.

I guess my car's loss is a lot less because I did try lowering my speed by 10 mph once starting after I filled my tank. I didn't notice any difference at all. I still had to fill her back up after driving it for the same number of days.

You need to figure out your mpg. Fill up the tank fully. Drive it until you're ready to fill up again. Take the miles traveled and divide it by the amount of fuel you put into the car.

No offense to you, when people provide information based on how far they can drive on a full tank/how many days they can drive on a full tank, it is irrelevant and imprecise when trying to figure out a difference in driving style. Granted, if by "eye balling" you don't notice a difference, then it probably isn't significant on your commute.

Every mpg counts, depending on how much you drive, it could save you a pretty penny.
 

Chiropteran

Diamond Member
Nov 14, 2003
9,811
110
106
Originally posted by: Xavier434
The only problem with that logic is that you do not get 3.5 hours in a lumped sum to do whatever you want. You are forced to spread it out in 5 min increments twice a day. That's pretty worthless.

Nonsense, you can get the time whenever you want it. You can go to sleep 5 minutes later so your evening time is 5 minutes longer, it's not like you are forced to take the 5 minutes apart from all your other free time which would leave you with nothing to do with it.
 

Xavier434

Lifer
Oct 14, 2002
10,373
1
0
Originally posted by: mariok2006


You need to figure out your mpg. Fill up the tank fully. Drive it until you're ready to fill up again. Take the miles traveled and divide it by the amount of fuel you put into the car.

No offense to you, when people provide information based on how far they can drive on a full tank/how many days they can drive on a full tank, it is irrelevant and imprecise when trying to figure out a difference in driving style. Granted, if by "eye balling" you don't notice a difference, then it probably isn't significant on your commute.

Every mpg counts, depending on how much you drive, it could save you a pretty penny.

That's pretty much my point when it comes to my commute with my car. The difference was so small that I concluded that the juice just isn't worth the squeeze.



Originally posted by: Chiropteran
Originally posted by: Xavier434
The only problem with that logic is that you do not get 3.5 hours in a lumped sum to do whatever you want. You are forced to spread it out in 5 min increments twice a day. That's pretty worthless.

Nonsense, you can get the time whenever you want it. You can go to sleep 5 minutes later so your evening time is 5 minutes longer, it's not like you are forced to take the 5 minutes apart from all your other free time which would leave you with nothing to do with it.

That's still not a lumped sum which is my point. Unless I can get at least an extra 15 min per day to do whatever I want after work then it holds very little value to me.
 

Chiropteran

Diamond Member
Nov 14, 2003
9,811
110
106
Originally posted by: Xavier434
That's still not a lumped sum which is my point. Unless I can get at least an extra 15 min per day to do whatever I want after work then it holds very little value to me.

/shrug I guess we agree to disagree.

If I'm losing 5 minutes here for $.50, it's just as bad as losing an hour for $6.

Are you are the type of person who doesn't mind commercials? They only waste a few minutes of your time and such a small amount of time holds very little value to you. I'm different, I hate wasting time.