fuel usage Vs speed

fesuvious said:

Another side to this;
If you increase the overall diameter of your wheel&tyre combination you will be as a result achieving lower engine RPM at your desired cruising speed.
If you used GPS to be certain of the speed then,. for example if currently 2300rpm is 56mph then on a larger diameter wheel&tyre its possible to reduce this somewhat..
Can someone do the maths?

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It's a direct relationship.  If a given tire diameter yields 56 mph at 2300 rpm, then a tire with 10% larger diameter would yield 1.10*56=61.6 mph at 2300 rpm.

I understand that everyone wants to save money, thus get better milage, but at what cost.. if you set your cruise on 62 mph, to save fuel, but lose speed on the hills what did you gain? If you drive say 75mph, you already have a jump on the hill over the 62mph guy so won't it all even out in the fuel consumption? besides if you drive anything but 65 or 70 you will get run over, no one even uses their blinker to signal a lane change anymore. our mh get 5.2 at 62-65 it gets 6.4-7.2 at 73mph..and one time..some how we got 8mph. I met a guy with the same set up as I and he sets his cruise on 57mph, and say's he gets 8 all day long..I told him good thing, cuz you might as well get something outta the deal, when it takes you an extra 2 day's to get where your going..lol

Kevin:

I set out this summer deciding to slow down to 62MPH to conserve fuel and it has provided an 8% saving over the first 3600 miles; so it does work. Also I found that many of the larger trucking firms have slowed their fleets down so I wasn't alone in the right hand lane. Staying at 62 really does make for a relaxing trip with very few times having to switch lanes as you pass someone slower. It also lets the Tradewinds loaf along at lower temps.

It hasn't required anywhere near the determination I though it would. ;D

We had also reduced ourt speed to around 62 MPH previously but on this trip we decided 60 was fast enough after all we are not in a real hurry.  We have enjoyed travel at 60 MPH thus far.

Okay, now you people are confusing me (maybe even scaring me)....

I am driving my new purchase, a 1996 Vectra (34'), home alone from Mesa AZ to Vancouver Island BC. I pick it up Tuesday morning.

I plotted the most direct route but one that goes through Salt Lake as I have a friend there. Seems now I am told that the route is fraught with high grades but that was not bothering me really as I am from BC. On the other hand, I do not even know what a tank of gas costs in one of these LOL, nor have I ever driven anything this length alone. Our gas is way over $6 a gallon (your gallon and more for ours which is larger). I am hoping that the estimates I see here of no worse than 50 cents a mile to move a Class A are a reasonable way to avoid running out of gas....At this point, I just want to get my new 'home' home LOL...I figure I shall be primarily concerned with staying in my lane and on the road and not bothering anyone else.

What is the best speed to drive then? Our top speed here is 55mph (90 kmh). Will people be upset if I drive that there? Are there other suggestions anyone has that might help me, as a novice? I keep thinking of: "I am not afraid to go fast...It is crashin' and burnin' that worries me" (sign on my scooter LOL)....

If I average you all out (and discount the extremes), it sounds as if 60 mph or maybe 65 is best...and deal with the hills as they come... Am I right??

Thanks in advance...

jan

islandmomma, 55 is fine. I do it a  lot. If someone wants to go faster, they will  pass you.  : Gives them a thrill!  ;D

I get up to 60, now and then, but I'm in no hurry. I stay in the right lane and rarely pass anyone. I get passed a lot. If they can afford the gas to drive that fast, more power to them. 

Ray D  ;D

Jan

We just picked up our new "home" in Alabama at the beginning of June and drove it back to Edmonton AB doing 60 mph virtually all the way. As Ray says just stay in the right lane and enjoy the trip, let the others pass and you'll see them at the next gas station. BTW, on a 2500 mile trip we averaged $5.00/gallon between US & Canada.

If you haven't driven a class A before I recommend spending time with the seller getting used to the width and maneuvering in some safe but challenging area's. The first day on the road will be the worse, then you discover that it's not that bad after all. Enjoy your new life and keep us posted

Dale

Islandmomma:

Since we are headed to Canada for the summer you scared me with your "over 6.00/gallon fuel". 3.79 liters of fuel is one US gallon and at $1.50Cdn/Liter that should come out to about $5.70Cdn for a US gallon.

In any event you should get somewhere between 7-8 mph (or better) at 55MPH and at an average US price of 4.10US a gallon that works out to .55US a mile at 7.5MPG. In Canada that goes up to .76CDN a gallon.

Good luck and enjoy the trip.

Jeff

BC now has an additional Carbon Tax....So it could be over $6.00.

By the way the fuel surcharge on your trip is over a $100 more than ours...Betty will respond with more info in a private email.

Terry A. Brewer said:

Jeff

By the way the fuel surcharge on your trip is over a $100 more than ours...Betty will respond with more info in a private email.

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Terry:

The fuel surcharge went up to 27% July 1st. ???

Jeff Cousins said:

Kevin:

I set out this summer deciding to slow down to 62MPH to conserve fuel and it has provided an 8% saving over the first 3600 miles; so it does work. Also I found that many of the larger trucking firms have slowed their fleets down so I wasn't alone in the right hand lane. Staying at 62 really does make for a relaxing trip with very few times having to switch lanes as you pass someone slower. It also lets the Tradewinds loaf along at lower temps.

It hasn't required anywhere near the determination I though it would. ;D

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I guess my problem is, I don't have alot of time for driving, we plan our trips so we can have more time on vacation, than me driving. Have you noticed a huge time frame change from point a to point b?

what about hills..or should I say BIG hills, do you slow down in the 40's or slower when climbing them?
My cousin drives for a local company, and someone told them they could save a million a year by re-programing ther computers, not only to a slower speed around 62mph, but they all run super 10trans, and somehow they now have 9spd with power, but when you shift to 10th it's like an over drive, with no power..So now he gets stuck in the slow lane, can't pass anyone even going alittle under his speed if they are close to a incline, because it tachs out in 9th, then he shifts to 10th, and no power.

I guess my thing is I would love to get 8plus mpg, but after running down to florida this june... I got nearly run over doing 75mph. not to mention the lack of NO ONE EVER USING THERE TURN SIGNAL to change lanes!!!! (I've got a set of Air Chime train horns I'm fixing to mount in the front of this thing, and either get them to wake up...or watch them take cover) not the truck stop ones either...Kansas City Southern Railway..

There are several theories about fuel economy.  Perhaps the best strategy is to allow the computer in the coach to 'do the driving' for you.  Using the accelerator pedal as a 'shifter' usually results in less efficient operation of a coach.

Boy, this is another blog where everyone has an answer!God Bless America! I grew up in an era where the straight eight engines were due for a major rebuild with few miles in between. This was due to stress on the lower end. This is THEE difference between gas and diesel, DP"s run up the hill with fulll blower at less then 2,500 RPM's
in a higher gear the a gas engine red lining the Tach. Try 400,000 miles on a gasser before a major rebuild.

Well I started this string a couple of weeks ago and have read with interest all the replies.  I just returned home from a vacation on the shore of Maryland with family , MH + TOAD, I used my own links advice and kept the speed at 58 mph on cruise all the way, both ways. I  filled and did the math tonight, 9.22 mpg this compares to the exact trip last year at 65 mph both ways that resulted in 8.21 mpg. Same fuel from same tank and rig parked in same spot for fueling, same toad that weighed in at a hefty 5360 lbs , so maybe not a exact test as winds and traffic lights play a part,  but is most likely close to a accurate test. Will be heading from Hudson valley NY to Oshkosh WI, soon and will try to do 60 for trip , I will not have a toad  so hope to get 11 mpg or close to it, got 10.4 last year at 63-65, I will adjust speed to read 73 so I will feel like I am flying (better watch for smokey)!. 

I noticed a big diference by cruising at 57 mph on the right lane. i leave a couple hours earlier and enjoy the trip. no rush. besides, is safer at lower speeds with all this crazy people driving out there. also make sure your tire pressure on the rv and the towed vehicle is up to specs.

I think anyone driving a motorhome/bus 75 or 80 mph is definately out of their mind and has a lot more to worry about than milage. The safety of the people in their coach and the safety of others on the road. I drive my 460 engine at 55 mph on the road and average about 10 mpg. If also gives you time to enjoy the ride.

Well, I forget if it's 80 or 82 where my rig starts complaining (Driver Informaiton Display) that I'm going too fast (MAX VEHICLE SPEED)

Only went that fast one time

Accelerator full UP 

Down hill

Tail wind ... Well even at 80 mph the tumble weeds were passing me.

Went perhaps a quarter mile at that speed before I got to the bottom and slowed down

Great millage though

prevostman said:

There are several theories about fuel economy.  Perhaps the best strategy is to allow the computer in the coach to 'do the driving' for you.  Using the accelerator pedal as a 'shifter' usually results in less efficient operation of a coach.

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I'm not sure I understand your point or reference to "let the computer do the driving".  If by that, you mean to use the cruise control, I respectfully disagree.

harley man said:

"Boy, this is another blog where everyone has an answer! God Bless America!"    ya-da, ya-da, ya-da    "Try 400,000 miles on a gasser before a major rebuild."

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And this relates how ??? to fuel usage VS speed.

R1Kirby said:

I think anyone driving a motorhome/bus 75 or 80 mph is definately out of their mind and has a lot more to worry about than milage. The safety of the people in their coach and the safety of others on the road. I drive my 460 engine at 55 mph on the road and average about 10 mpg. If also gives you time to enjoy the ride.

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I run 72-75 90% of the time what makes you think I'm outta my mind? I've lost power steerning at 75mph, in the mh, and had a blow out at 80 in a 379pete. if your not on your game..or paying attention it doesn't matter if your going 70+or 55 your in trouble. I guess I'm different I don't kick back and enjoy the drive or scenery...I pay attention to everyone/everything around me..