gas usage over a mile with and without a stop.

A car drives exactly 1 mile at 45 miles per hour.
An "x" amount of gas is used.

The same car travels the same mile, but makes a stop. (braking, turn off engine, turn on engine, complete the mile).
I know the extra wear and tear on the brakes, ignition, etc. but is more gas used if a stop in made during this mile, than if no stop is made?

Thanks.
LVL 25
nickg5Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

owner66Commented:
Yes, it would use more gas. Not the stop and start, but the acceleration back to 45 as opposed to keeping a constant 45 would consume more fuel. I believe this is why they have highway and city mpg.
City refers more to stop and go traffic, while highway refers to travelling long periods at relatively constant speeds.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
nickg5Author Commented:
well, along my daily drives, I was stopping for a reason and I wondered if these stops were a waste of gas.
(Compared to the reason I was stopping, which was to get something off the ground for a project)
0
Lordy123Commented:
Yes you will use more gas. Think of how the car operates, specifically the gearing. To accelerate you bring your rpms up, shift, repeat.

Its hard to measure how much gas is wasted on stops, the answer is very dependant on your specific vehicle. Over all I would say measuring the inefficiency of one stop would be very insignificant.
0
Cloud Class® Course: Certified Penetration Testing

This CPTE Certified Penetration Testing Engineer course covers everything you need to know about becoming a Certified Penetration Testing Engineer. Career Path: Professional roles include Ethical Hackers, Security Consultants, System Administrators, and Chief Security Officers.

Michael-BestCommented:
Yes in two ways:

1/ Inerrcia: the inercia lost in breaking must be recovered by acceleration (a steady drive(r) will always be more fuel efficient)

2/ Engine starting inercia and wasted fuel: the engine needs inercia to overcome its stopped state and extra fuel to start and usually extra revs over the idle speed (leaving a engine idling for a short time (that time depends on engine type and size) will use less fuel than restarting it)

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

The idling stop that is being promoted by governments / car makers may or may not have any fuel (emission) savings depending on the stop time.

http://www.greencarcongress.com/2005/10/mazdas_new_smar.html

Hope this infomation helps.
0
Michael-BestCommented:
Sorry my answer was being typed when you closed the question.
If you feel I have added useful info. to your question you may re-open and reassess the answers.
0
nickg5Author Commented:
re-open.
how?
0
Michael-BestCommented:
click the "request attention"
And give you request for a moderator to action.

 
0
nickg5Author Commented:
ok it says pending.
0
Michael-BestCommented:
Thankyou
I was delayed, I / we have power outages / shotage here in Tokyo, Japan.
0
nickg5Author Commented:
I am not concerned about an ounce of gas, here and there.

But, for the physics or the automotive aspect of it:

If I want to pick something up along the road, should I:

1. stop, get it, restart engine, and go?

or

2. slow down to a crawl (or a stop) without turning the engine off, grab the item, and then leave?

Thanks.
0
Michael-BestCommented:
# 2 would be much better for your engine and fuel (gas).
Your engine starts with no oil pressure until the oil is up to pressure and flowing through all moving parts, bearings, etc. you have more friction causing wear.
Also as I stated in: 30/03/11 03:12 AM, ID: 35243868
Engine starting inercia and wasted fuel: the engine needs inercia to overcome its stopped state and extra fuel to start and usually extra revs over the idle speed (leaving a engine idling for a short time (that time depends on engine type and size) will use less fuel than restarting it)
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Automotive

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.