There are several simple acts that we old guys could adopt without too much effort to act a bit more responsibly toward protecting the environment and decreasing the effects of climate change. Most involve altering an existing habit or adjusting to a new one , like adopting a recycling habit, or replacing incandescent light bulbs with compact fluorescents. In most cases it requires us to do something. And there’s the rub.
Once we old farts have settled into our comfortable habits, they stick with us as if attached by crazy glue. And to change–like setting up an additional can for recyclables, for instance–requires us to: 1) Make the decision to establish an in-house recycling can, 2) Obtain a recycling can, 3) Find a place to put it, 4) Make decisions every day of what is recyclable and putting it in the new can, 5) Trying to remember not to put the coffee grounds in the recycle can, 6) finding out where to empty it when full, and 7) Physically taking it to the recycle center to empty it.
No wonder we don’t take on such a formidable task—it’s a seven step process. Makes you want to take a nap just thinking about it. Mind you, a woman could probably whittle it down to five steps, which explains why more women become sensitive to the plights of Mother Earth than men.
Well, I’ve figured out a way to gently ease us out of the “set in our ways” category into a “green” practice with a minimal amount of effort. You do this while sitting down. It does not require you to exert any effort, and in fact, requires less effort probably than any of your present slovenly habits (asks your wife if you’re not sure what they are) that you practice without a thought.
I’m referring to reducing our highway driving speed from 75 or 65 miles-per-hour to between 55 and 60 mph. Now don’t gasp, it’s not that daunting a task.
It simply requires us to exert less pressure by the bottom of our foot on the accelerator pedal of our truck or motorhome. That’s all. Try it. Just lift your foot an eensy teensy bit. And voila! Your speed will decrease, and to stay on target, you can monitor the speedometer right in front of you without having to get out of your comfortable drivers’ chair.
And here comes the pay off. Most cars achieve the best mileage figures when driving between 45 and 55 mpg says Patricia Monahan, deputy director of clean vehicles for the Union of Concerned Scientists. In an interview in the San Francisco Chronicle, Monahan explains that for every mile per hour over 60-mpg, fuel economy drops by about 1%. And it gets worse as you creep up to 65 and even worse at 75. I improved my gas mileage from 7.3 mpg to 8.6 mpg by staying below 60mph (and avoiding fast starts and stops)–an improvement of 17.8%.
Though the last study was conducted in 1997, it revealed that slowing from 70 to 60 mph improved fuel efficiency by 17.2%, and from 75 to 55 mph, the improvement was 30.6%! Now admit it, did you think that by simply raising your foot such a tiny amount could knock that much off your fuel bill? If you get this concept, it disproves that old adage, “You can’t teach an old dog new tricks.”
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Bob Difley
David – I am not much of a techie so I rely on the great comments like yours to steer me to those gadgets that I haven’t heard about. I will check it out. Thanks. Bob
David
I know this is a late reply but I do not get to read the blog everyday. I agree with the slowing down to 55 mph. When started going up last year, I sent emails to Lamar Alexander my congressman. I suggest that a bill should to lower the speed. I heard nothing and of course we all have seen nothing. Big Oil does not want to see any kind of bill like that. And oil has congress in their back pocket. Enough soap box!
I bought a ScanGauge II engine monitor. I can monitor my throttle position sensor, MPG, and 10 other standard readings from the engine computer. I also loaded 12 other gauges with their Xgauge function. The big one for me was the transmission temp since I have 99 Tahoe towing 6200# trailer. It simples plugs into computer port on the car.
http://www.scangauge.com/
David
Leo Everitt
While I agree that their is a sweet spot for an engine to improve fuel economy, I disagree with other statements i.e torque gets an RV moving but its HP that determines speed and speed does matter. Rather than expand I will simply reference this link for a more detailed discussion. It’s written for trucks but most applies to RV’s.
http://www.everytime.cummins.com/every/pdf/MPG_Secrets_Whitepaper.pdf
TXBrad
Wow ! Speed ( mph ) may or may NOT have a real impact on Milage !
An engine uses fuel to produce troque to move an RV/ tow vehicle.
Aerodynamics & weight require more power to move = more fuel.
Pulling hillsmountains also takes more power. Diesel engines more so than gasoline, need to operate at their optimum RPM. Too slow will burn more fuel than too fast.
I believe the best speed to drive can be helped by using a Tach. Many tow vech & motor-homes have them & this is a cheap thing to add.
Then watch the tach vrs the speedo. Once that big /heavy rig gets rolling,you can see the rpm’s decrease. You can check what the lowest rpm
gives you the best mpg. Engines have a curve RPM vrs torque & one can play w/ optimum rpm. Less rpm of engine @ safe speed = best mpg.
Bob Difley
Great comments all. Thanks for the participation and discussion. I think that, even as the original poster, I learn the most.
jack francis
More for Ian:
With a little work, I think we could be buds.
jack francis
Thank you, David. I heartily agree with your statement that “…too slow can be as bad for mileage as too fast.” And I would add, “Too slow can be as bad for safety as too fast.”
And for Ian, your are absolutely right, the CHP will will not consider 55 MPH as to slow – unless the body of traffic is moving at the posted speed limit of 70 and the vehicle is not towing a trailer, and it is creating a hazard by causing a pile-up behind it.
Common guys! This is not a p—ing contest. All I am suggesting is that we recognize reality in our highway driving conditions today, and that we work together to get more rational speed limits in the near future. If the average speed of the whole body of traffic on any given highway at any given time was 10 mph slower, we would each cut our gas costs significantly, and our added trip time would insignificant – probably less time that we spend on the loo in the morning.
And more for Ian: I have this troubling mental picture of a trucker -who expects everyone to be driving 10 or miles an hour over the speed limit – running into the back of your 5th wheel when you are driving 55 MPH in a 70 MPH zone. And I am trying to picture what you do when you are driving your car in a traffic jam at 55 MPH in a 70 MPH zone behind a truck, an RV, or a little old man.
David
In general I support the article as written. Even people driving conventional cars and trucks could benefit by these actions. But I also have to argue the point just slightly based on this one statement: “Though the last study was conducted in 1997, it revealed that slowing from 70 to 60 mph improved fuel efficiency by 17.2%, and from 75 to 55 mph, the improvement was 30.6%!”
During the first fuel crisis back in the early 70’s, cars, trucks and RVs were neither very aerodynamic nor were they geared to get their best gas mileage at such a slow speed. Even in the 90’s, cars were geared to operate at higher speeds and the gearing today, designed to reduce engine RPM (revolutions per minute) have an adverse effect on mileage; up to a point. The aerodynamics have changed so that the amount of power needed to overcome drag is lower. This is basically known as the “drag coefficient” and with some cars it seems the coefficient is so low you could pedal along like a bicycle were it not so heavy. But RVs and certain other vehicles don’t have this advantage.
When you don’t have an aerodynamic advantage, you’ve got to use your powertrain in the manner it was designed. For a motorhome, this means driving it like a truck. Essentially that’s what it is, a truck chassis dressed in fancy aluminum or fiberglass and made into a home on wheels. This also means that most motorhomes should follow the truck speed limits in states where separate speeds are posted and really they should drive at lower speeds anyway for simple safety reasons. Something that big and heavy just can NOT maneuver or stop as quickly as a car. The benefit is that you quickly see a savings at the gas pump; as several responders to this post have acknowledged.
But cars and other tow vehicles have a different problem. Through personal experience, I know that a lot of vehicles with 4- or 5-speed automatic transmissions won’t even shift into the gas-saving top gear until somewhere between 50 and 60 MPH. This usually has the engine running at such a low RPM that any uphill grade at all will force the transmission to shift into a lower gear just to make the climb and if that’s delayed too long, it may be forced to drop another gear. Today’s cars, on average, really won’t get their best mileage unless you’re doing between 60 and 65 MPH.
However, towing an RV of any kind unless the absolute smallest is going to create enough drag by weight alone to load your engine if you run in high gear. In fact, if you study your Users’ Manual you received with your vehicle, you will note that they emphatically insist you do not attempt to use Overdrive (the top gear indicated by the letter D in a box on your gear selector indicator) while towing. The result, you MUST slow down to the 55 MPH range for best economy. I can tell you now it’s not that many RVs I find on I-95 trying to run 10 MPH below the posted speed limit in Maryland.
I have to add one more point. Your vehicle gets its best gas mileage in road gear at road speed, whatever that may be for your particular vehicle. Until you get to that speed, you are burning more fuel the longer you take to get to that speed. You have to work out a rate of acceleration that gets you to road speed quickly but not to the point you’re pushing the engine to high RPMs to get there. In other words, you don’t want to “jackrabbit” away, but neither do you want to accelerate so slowly that you drive 1 -2 miles before getting to road speed, either. This is something I see every day by people trying to overcompensate for the high fuel cost.
Your best economy is going to come where the car shifts quickly between gears and stabilizes at highway speed shortly after finding road gear. With a 6-cylinder engine this means letting it shift around the 3,000-3,500 RPM range as you start from a dead stop and probably shift into road gear just at 3,000 RPM. A V-8 engine would operate similarly in the 2500 RPM range. Towing your trailer will probably want you maintaining a little higher RPM than driving without, so if you drive normally at 2000 RPM without a load, you’ll probably want to drive about 2200 to 2300 RPM with, even though you’re not running in overdrive.
I personally drive a new Jeep Wrangler which is about as aerodynamic as a box on wheels and people are amazed when I tell them I’m getting nearly 25 MPG on the road when they’re lucky to get the rated 19 MPG. Even my in-town mileage is visibly above the rated mileage despite the fact that I pull away from the over-cautious at every light while other drivers seem to do everything they can to get past me before the next light.
To get your best mileage, you have to moderate at both ends. You don’t want to accelerate too slowly and you don’t want to drive too fast. Each vehicle is different. Find the speeds that work for you and you can demonstrate as much as 25% better economy over someone else with the same vehicle. Just remember; too slow can be as bad for mileage as too fast. Find that median speed and stick to it.
Ian McKee
No, Jack, I don’t drive my car at the same speed as my RV because 1) it is way more maneuverable, 2) it gets way better gas mileage at highway speeds and 3) I have a lot better visibility of the road and traffic.
Even in California, 55 is not considered by the CHP as too slow.
Ian McKee
I have driven a 36′ fifth wheel with a Ford F-550 for the past two years covering over 20,000 miles, and I almost always drive at 55 on the highway.
I don’t drive in the left lane except for passing and rarely has any other driver expressed displeasure. On that rare occasion it is always a hotshot who would be unhappy behind me even if I were doing 75.
Staying with the status quo until someone else lowers the speed limit is just an excuse.
jack francis
Thanks to Bob for a thoughtful response. Two things come to mind.
1. In California, my experience is that few if any RV towing another vehicle observes the 55 MPH limit.
2.Certainly, most trucks do not observe that limit.
3. I do not know statistics evolving from people driving too slow. I also do not know the statistics from people driving too fast. I do know that in California, either behavior is considered a violation and subject to citation.
Common sense (and personal observation) tells me that driving at a speed a lot slower than the general flow of traffic results in “bottlenecks”. I am sure that we all agree that such bottlenecks are a breeding ground for accidents. Again without statistics to support my opinion, most freeway accidents occur in traffic slow-downs, i.e. front-to-rear or lane changing collisions.
As an aside, it is common for drivers to run into the back of a slow moving truck.
I surely don’t want this to become a debate. My intent is to draw attention to the fact that all drivers could benifit from the increased safety and reduced cost of driving slower, without suffering a meaningful increase in trip time.
Personally, I will drive a little faster than my best fuel economy speed, and a little slower than my best time speed. A little compromise goes a long way toward a happier, safer experinence for everyone.
Does every RV owner drive his/her personal car at the same speed that they drive their RV?
Leo Everitt
I was saying that if one doubles your speed it will take 8 times more horsepower i.e. the cube of 2 is 8.
Bob Difley
Jack – I’m not sure that slowing down causing those behind you to slow down causes accidents. I’ve never seen such statistics. However, I would agree that slowing down to 55 mph in the fast lane where the speed limit is 70 could pose problems. Almost everywhere, the speed limit for a vehicle towing another is 55 mph and these vehicles are supposed to drive in the right hand lane except to pass. It works for me. If I get behind a slow moving truck (I don’t see drivers running into them from behind) I simply move over one lane, pass, and move back. All driving rules require using some common sense, but not slowing down to the speed limit (not necessarily below, as that could cause problems) because you think it will save lives seems like a cop out for justifying continuing to drive as usual, just as in the 70s when the “driving public rejected the idea”.
If you know of some statistics on accidents caused by people slowing down to the speed limit, please let know. And thanks for the discussion-stimulating comment.
Bob Difley
Let ’em honk. It’s their problem, not yours. Part of the relaxation part of driving slower is not letting things that don’t matter get to you. What I do is wave back at them with a big smile on my face. Bet it drives them crazy. And now the airlines are following, slowing down their flights and saving scads of cash. It’s a trend.
What do the rest of you–especially the nay sayers–think?
jack francis
I have this vague (read “senior”) memory of the national 55 MPH speed limit. That was a decade or two ago. It was established in response to higher fuel prices and rising accident/injury rates. The obvious thing is that it worked!
The equally obvious thing is that the driving public rejected the idea. We accepted the higher cost-per-mile and the higher casualty rates because we wanted to go faster and get there sooner, to Hell with the cost in dollars and human suffering.
We can drive slower and save. When we are driving at 55-65 on highways with 65-70 max speed limits, we will enjoy the benefit of increasing our gas milage.
It is a fact that the general public drives at 70+ on our highways. Therefore, when we drive at our fuel-saving lowerer speeds, we are going to slow the traffic behind us. The sad result is that there will be collisions resulting in property damage, personal injuries and even loss of life.
As for me, until the entire driving public embraces saving gas (and lives) by driving slower, I am going to drive at the average speed of the roadway I am traveling.
As for me, I am going to drive at a speed that does not create a bottleneck to traffic, and add to the potential for a bad accident. I hope that means 5 MPH below the posted limit. I hope it is no more than 5 MPH above the posted limit. I will pay the cost-per-mile to contribute to my safety and to the safety of others.
If we really care about safety, and cost, let’s work to restore lower speed limitsl. The higher speed limits result in higher cost-per-mile in fuel consumption, but more importantly in higher accident rates and more serious injuries from those accidents.
The not-so-obvious message is this: Drive fast and your per-mile cost will be higher, and you will be more likely to have a serious accident. Drive slow and your per-mile cost will be lower, and you may contribute to a serious accident for others.
If you are passing everyone else, you are driving too fast. If everyone else is passing you, you are driving too slow. Drive at a speed that keeps you in the flow of traffic. Don’t let either time or cost determine your best speed. Safety is more important.
Dalton Tamney
Now if we can just get the speedsters to stop honking at us or giving us the finger just because we’re not driving 10 or 20 MPH over the speed limit.
Bob Difley
What great comments. Sometimes I think it is like the donkey story where the prospector whacks his donkey on the head with a two by four. The dude reacts in shock, and asks why he did that. The Old Timer replies that first you have to get their attention. There is no better way to get the attention it deserves that with those first person affirmations (even though, Leo, I have no idea what you are talking about with that “2X speed= 8x HP”).
Wayne, it also seems like we can’t let go that we don’t have to arrive by a certain time or “make good time.” The only schedule should be the one we put ourselves on, and that can certainly be a more relaxed one, shedding our “Type A” need to be always in a rush. And Lynne, so true, I ran out of words before mentioning how much more enjoyable it is driving slower and enjoying the scenery while releasing the tension of driving faster.
Lynne Caulkett
I just returned home (Spring Hill, Florida) from a trip to Hiawassee, Georgia. I kept my speed on I-75 at between 60-62 just to see what kind of a mileage difference it would be and I was astounded! Not only did I get much better gas mileage with these rising gas prices, but I actually enjoyed the slowdown. I was content to let the speedsters pass me by and even took the time to enjoy the passing scenery which I don’t usually do, trying to maintain higher speeds. It was a much more relaxing drive and I will continue to travel at lower speeds. Green can be fun!
Wayne Bowen
Hi Bob
Just want to add support to your slowing down piece. Recently on a 3,000 mile trip in our Winnie, 8.l L gas, I lowered my speed from 65-70, at which I was getting 7 mpg, to 58-60 and mpg increased to 8.4. Hey, what the heck, we’re not meeting a deadline so just relax and save gas/money!
Wayne
Leo Everitt
Now admit it, did you think that by simply raising your foot such a tiny amount could knock that much off your fuel bill?
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Those who paid attention in class will have all ready gotten it.
Aerodynamic losses are a cubic function of speed i.e 2X speed= 8x HP
One thing that the front of an RV is not aerodynamic.; for which one defintion is “Having a shape that that is not adversely affected by wind flowing past it”.
As someone said its more like a billboard.