How do I maximize MPG? from miles per hour

[mikeleblanc413]

I've been so very lucky to have this incredible teaching opportunity come my way...I'll be teaching the children who travel with the Carson and Barnes circus...shortly, I'll be leaving Texas for Wyoming to meet with the circus...in your experience, what miles per hour has maximized miles per gallon. I have a 2000 Winnebago Minnie Winnie, V-10, total weight is 1500 below maximum...all thoughts appreciated.

[ronfisherman]

In 1972 you did not have data to read. We now have it. The ScanGauge II will read info that there are not gauges for in the instrument panel.
I was using a Vacuum Gauge on my cars in the early 60's. Much prefer the information that my ScanGauge II gives me. I can also see the Vacuum in the manifold. It is displayed Manifold Absolute Pressure (MAP) or Boost (BST) for a turbo.

[pnichols]

Things like expensive Scanguages IIs didn't used to be necessary in order to fine-tune gas mileage.

A vacuum guage is all that used to be necessary to do this. Just watch it as you drive and maintain the least vacuum reading you could at all times by controlling your speed, the gear you were in, and how far down you were pressing the gas pedal. I mounted a vacuum gauge in our 1972 Dodge van camper way back when and it helped us regularly get 17-18 MPG on trips with it's 318 V8 engine.

Now days I guess you have to use gadgetry to do the same thing.

[ron_dittmer]

tpi wrote:
I find it kind of a sport to try to get the best mileage out of the thing. It is actually something I enjoy if you can believe it. And chatting about it is kinda fun too.

I feel the same.

As for my wife and me taking a 5000 mile trip, if we can improve our fuel consumption by 10% through a change in driving behaiviors, that could add up to near $200 in savings. It's a payback sport.

Our recent investment in a $160 Scangauage-II should be a fun tool to help us in this sport. I look forward to our next 4 week trip this summer, putting this new tool to work.

[tpi]

crawford wrote:
To all why are you worrying about MPG, what are we talking about maybe 20 or forty dollars if you are you shouldn't be driving your coach. Enjoy you trip and being with your love ones. Just have safe and happy camping trip and stop worrying about silly stuff your trip will be great then.

Why participate in a fuel economy thread if you find the topic silly?

FWIW I find it kind of a sport to try to get the best mileage out of the thing. It is actually something I enjoy if you can believe it. And chatting about it is kinda fun too.

[pianotuna]

Hi crawford,

I paid $37k for my class C and drive it about 1000 miles per month. I guess I'm one of the lucky ones.

crawford wrote:
I think most campers would be lucky to see 4 to 5 thousand a year and spending 80,000 or more for a coach.

[Rolin]

We traded a Chev based MH for the Ford based MH. In the Chev 8.1 the scan gauge would go to 99999 when coasting down a steep hill. I assume because the injectors shut down. On the Ford V10 the best I get is mid to high 40's. Not sure why.

Enjoy learning more about the V10 and transmission combination. Helps minimize our stops at the refuel depots.

[crawford]

I think most campers would be lucky to see 4 to 5 thousand a year and spending 80,000 or more for a coach. If it were a car yes it's not silly, but for a camper which was never sold as one it is what it is. Suck it up and enjoy ,if this is your like so be it it sounds like buyer remorse.

[Flarpswitch]

Driving at moderate speeds is about the only thing I can do that has a payoff. The last round trip of 400 miles proved it to me. The route was half on the Interstate (65mph max) and state highways (55mph max). On the Interstate I chose to go with the truck traffic that is restricted to 55mph, but they cheat a little. Many of the trucks do drive at a consistent speed to save fuel and avoid heavy fines. So I just settle in with the pack. On the state roads, I just take my time and try not to impede traffic by letting the jackrabbits use the passing lanes. Normally I get 15+mpg average. On this trip I got nearly 18mpg. Doing a little math, I figure that's a bonus of about 50 extra miles. At 70-75 mph I will get close to 14 mpg. On my last 10,000 mile circuit around the country through 24 states, if I made an effort to keep to not more than 60 mph, I figure I would have saved about $400. And, if you are worried about climate change, the difference would be about a ton and a half less carbon in the atmosphere. I have an idea. If I drive slower, can I get Carbon Credits and sell them through that crook Al Gore?

[pianotuna]

Hi crawford,

Where I live gas is now $5.269 per US gallon. Saving fuel is not silly, especially on a 1000 mile trip.

[crawford]

To all why are you worrying about MPG, what are we talking about maybe 20 or forty dollars if you are you shouldn't be driving your coach. Enjoy you trip and being with your love ones. Just have safe and happy camping trip and stop worrying about silly stuff your trip will be great then.

[Westronics]

skipnchar wrote:
The main REASON you get better mileage at slower speeds is because of the wind resistance. For that reason your optimal speed/mileage combination will change depending on wind direction. It will PROBABLY be slower than you want to drive on the highway when winds are on the nose. Best you can hope for is to just go slow enough that you get as much fuel economy as you can STAND to get for the driving you're doing. MOST of the time your actual optimal speed will be around 20 MPH.

The actual optimal speed on flat terrain is the lowest speed at which you can keep the transmission in Overdrive. That would be at 40 MPH. Coincidentally, that is also the speed at which wind resistance starts to become a big factor in fuel burn. Unfortunately, 40 MPH is often too slow to be safe, so the answer is to keep your speed down as much as you can, within reason. You can achieve 16 MPG or more at 40 MPH on flat terrain with no stoplights, but no one ever gets to drive like that.

The best I have ever done for a full tank is 13 MPG when making an all-highway run at 55 MPH with, possibly, a small tail wind.

I, like many others, use a Scanguage II and adjust my driving based on its feedback.

[mikeleblanc413]

I left Southeast Texas on Friday for Wyoming and followed much of the advice given on this post. On three tanks I have done 10, 10.5, and ll.15. Basically 50 MPH, no cruise control, with the exception of flat land...I NEVER thought I would get such mileage...THANK YOU! Right now I'm in Valentine, Bebraska and will arrive in Wyoming in the morning.

THANK YOU so much for such sage advice! Have a GREAT week-end!!!

[pianotuna]

Hi tpi,

I may be wrong--it may be going to all nines on a long enough hill. Not too many hills where I live, so it will be a month or more before I can check that out.

[tpi]

29 is much as you see? My factory gauge has shown mid 30s on a coast. My Scangauge on my former '04 Camry would show 99 mpg because it seemed to cease injection under some coast. Evidently the V10 never ceases injection.

Or on downhill you are seeing no injection? Could be it is common these days..