Does anyone know whether you get better gas mileage in interstate driving by using or not using cruise control? Are there any studies that have been made on the subject?
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MPG and Cruise Control
- Thread starter Cyrano
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scooter123
Member
There have been studies done by the DOT and IIRC cruise control normally yields a 3-5% improvement in economy. As for why, cruise control is smoother in throttle response to changes in grade, so less fuel is wasted by over accelerating then slowing down.
However, fuel misers can get better mileage if there aren't any police around. Because if you use the downhills to build up a bit of extra speed you can use that speed to carry you part way up the next hill without having to hit the gas. Unfortunately the Police aren't very understanding with those running 85 mph on a downhill to gain enough inertia to carry them up the next hill.
However, fuel misers can get better mileage if there aren't any police around. Because if you use the downhills to build up a bit of extra speed you can use that speed to carry you part way up the next hill without having to hit the gas. Unfortunately the Police aren't very understanding with those running 85 mph on a downhill to gain enough inertia to carry them up the next hill.
Lots of studies done. CC definitely improves the MPG. The computer in your car is more consistent than your foot. Heck, if I tried to keep my leg in the exact same position to keep the throttle steady my knee would lock up and I couldn't walk when I got where I was going. Of course, setting the cruise at 80 versus no cruise at 65 you'll get better MPG at 65. I get way better mileage going thru Oregon where the limit is 65 than when I'm in California going 80. Yes, I know, the limit in Cali is 70 but if you're only going 70 you're holding up everyone.
Edit: I guess I'm too long-winded. Two people posted while I was typing!
Edit: I guess I'm too long-winded. Two people posted while I was typing!
Using the cruise control does give you better mileage. It also protects you from getting a ticket. Municipal governments are starving for $$$$$$$$$$$. What some people do not know is that a municipality or agency tortures and hound cops to issue tickets. It doesn't happen everywhere, but in a lot of places it does. Some agency heads still leave the option up to the officer and do not place an urgency on tickets. This is rare.
A lot of places are using video speed cameras, it just does not pay to speed.
A lot of places are using video speed cameras, it just does not pay to speed.
One of my cars offer an instant MPG reading and also an overall MPG reading.
I do not look at the odometer but rather drive by the MPG readings and the tach. I get 31 MPG out of a full size car doing so with in and out of town driving. The lady that lives here just to keep me broke drives using the speedometer and could not care less about mileage. She gets 20MPG on the same car. Good thing about that is she does not drive 250 miles per year.
Cruise control for me in this area just does not work well. Start up a small hill on the interstate and it puts the vehicle in passing gear.
Another of my vehicles gets 8 mpg going uphill, down hill, around the hill, through the hill or with cruise control on or off.
I do not look at the odometer but rather drive by the MPG readings and the tach. I get 31 MPG out of a full size car doing so with in and out of town driving. The lady that lives here just to keep me broke drives using the speedometer and could not care less about mileage. She gets 20MPG on the same car. Good thing about that is she does not drive 250 miles per year.
Cruise control for me in this area just does not work well. Start up a small hill on the interstate and it puts the vehicle in passing gear.
Another of my vehicles gets 8 mpg going uphill, down hill, around the hill, through the hill or with cruise control on or off.
steveno
Member
on long drives cruise control sure saves cuts down on the fatique factor which to me is worth it. especially on long drives
This past Summer my wife and I took a two-week 2,500 mile road trip up through Washington, D.C., New York City, Boston, New Hampshire and back. We averaged 41MPG at normal routine highway speeds on the open road and in the city. I used cruise control except of course in city driving. Car normally gets about 39 w/ ethanol gasoline. Since ethanol gasoline is all that was available on the trip, I figure the 2MPG improvement was probably the result of using the cruise control.
My 2007 Jeep Wrangler Rubicon 2 dr is a slug, with a 3.8 leftover minivan engine. With the cruise set it hunts up and down betweem 2nd and 4th at 60 mph. I do better anticipating hills myself. It also regularly accelerates well above what the cruise is set at, before settling in at the set speed. I attribute all this to a too small engine, and the hills I live in. Headwinds will also force continous downshifting with or without cruise. You have to lockout overdrive. Oh, and this *** gets 17 mpg @ 60 mph.
Faulkner
Member
I've been in law enforcement for 17 years and have never seen this. Never. Must be a regional thing.
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Big Cholla
Member
I am acquainted with a major study done by a Fed. Gov. agency on maximization of fuel mileage on full-sized pickups. The No. 1 conclusion was to use cruise control when possible. The the driver should take off the outside mirrors or fold them in, over inflate the tires and run with the tailgate down. All gave measurable increases in fuel economy. Nothing else much mattered. ...... Big Cholla
USAF385
US Veteran
The general opinion is that cruise control increases efficiency, but depending on the terrain it could decrease it. For example: I helped my brother move down to State College recently and found I get better mileage on that trip when I don't use the cruise control.
nicky4968
Member
Not just MPG. I bought a nice Suzuki Forenza for my travels. There is a button marked "Hold". What exactly it does, I don't know. But it is not a cruise control as I thought it was. The car has no cruise control.
Take a drive sometime from Littleton, Colorado to Portland, Seattle, or Kansas City without cruise contol.
I thought of putting in a hand throttle, but was told you can't do that anymore.
Take a drive sometime from Littleton, Colorado to Portland, Seattle, or Kansas City without cruise contol.
I thought of putting in a hand throttle, but was told you can't do that anymore.
This is absolutely not true for newer (post 1983 approx.) trucks. Newer trucks are designed such that the air coming over the cab re-attaches at the tailgate and the air in the bed forms what is known as a "bound vortex". The bound vortex actually acts like a "fastback" surface. I work at a large scale wind tunnel where we have performed thousands of hours of automotive tests and have actually measured the drag on pickups with tailgate up and tailgate down. The "tail gate up" configuration produces measureably lower drag, and therefore higher fuel mileage.
I know that the 89 Ford F150 was windtunnel tested with the tailgate up. AC on, cab to temp, and windows up, make a bigger difference.
Just like the autopilot in an airplane, cruise control in a car takes the human element out of throttle openings. It's much more precise and efficient than the driver's right foot.
As an aside: As a motoring enthusiast, I used to hate cruise control. My feeling was that in using it, I was giving up control of my car to a machine. When I gave it a try, I realized that what it actually does is relieve the driver of having to constantly monitor speed, and lets him concentrate on the other elements of driving. I now use CC every chance I get.
