Good mileage results with a light foot

Gary CA · 08-25-2008, 04:33 PM

Just completed a 2600 mile round trip from So. Cal to Seattle WA. Tow vehicle was left home. Traveling on level interestate (Allision Trans on ECON MODE) between 55-57 MPH I got 9.5 MPG; interesting to note that most company owned big rigs were traveling the same speed. When we reached more agressive driving in the mountain ranges or winding coastal highways of WA and OR the mileage dropped off to 8-8.5 MPG. We left CA paying $5.29 per gal diesel and returned three weeks later to CA paying $4.39, good timing.

Traveling with a light foot pays off!

Gary CA · 08-25-2008, 04:33 PM

Just completed a 2600 mile round trip from So. Cal to Seattle WA. Tow vehicle was left home. Traveling on level interestate (Allision Trans on ECON MODE) between 55-57 MPH I got 9.5 MPG; interesting to note that most company owned big rigs were traveling the same speed. When we reached more agressive driving in the mountain ranges or winding coastal highways of WA and OR the mileage dropped off to 8-8.5 MPG. We left CA paying $5.29 per gal diesel and returned three weeks later to CA paying $4.39, good timing.

Traveling with a light foot pays off!

porscheracer · 08-25-2008, 06:55 PM

That's very true. The only flaw is that in most of the center of the country, driving very much under 60 will get you run over - by everything. Some states even have a 55 MPH minimum on the interstates.

We usually travel the backroads, even in the Vectra, because the mileage is usually closer, the speed limits are lower, and the scenery is better!! I use the "shortest route" option much more often than "quickest time" on the GPS.

John_Canfield · 08-26-2008, 08:44 AM

We have an interesting comparison between last summer's travels and this summer.

Last summer:

8800 miles
Interstate average speed - 65mph
average MPG - 7.8
terrain - Texas to Midwest to NY state to Midwest to Texas

This summer:

5500 miles
Interstate average speed - 60mph
average MPG - 7.8
terrain - Texas to San Diego to Texas to Iowa to Colorado to Texas

I fully expected to improve our mileage by dropping our Interstate speed by 5mph, but obviously it didn't happen. Apparently punching into the west winds on the way to SoCal and the Colorado mountains kept us from showing an improvement.

porscheracer · 08-26-2008, 10:14 AM

John, I've noticed the same thing. Our coaches are identical in several respects, and mine doesn't do noticeably at 60 than at 65. And, since the prevailing winds in the midwest are west to east - they make more difference than anything else.

Of course, with my luck, I always seem to be traveling into the wind.

SargeW · 08-26-2008, 06:31 PM

In the couple of months that we have been full timing I have pretty consistently set the cruise at 60-62 MPH. I am averaging about 8.5 to 9.5 MPG pulling our 5K Jeep Unlimited. I have found that by keeping the speed just above 60 will keep me in 6th gear, and econo mode helps a little too. The minimum posted speeds we have seen coming across the northern midwest was 40 MPH. The max has been from 65 to 75 MPH, but most folks are not driving the max when it is 75. Even the cars are back around 65 to 70. The price of gas has really made an impression on people!

Sarge

porscheracer · 08-26-2008, 09:13 PM

The minimum speed limit discussion(s) got me off on a Googling tangent - which turned up some interesting data. Vehicles traveling at or below the posted minimum (or a 25 MPH differential, whichever is applicable) are 63 times more likely than the average vehicle to be involved in an accident. That's approximately 7 times worse than the numbers usually quoted for DUI's!!! Yikes.

codgerbill · 08-27-2008, 02:43 AM

I cant speak for other states but the posted minimum for freeways in Michigan is 45MPH. If I did 45 in MH or car It would totally PO everyone on the road and I do believe it might bring the wrath of road rage down uponst me from those not able to control their emotions.

MrTransistor · 08-27-2008, 07:57 AM

Hi Gary & John,

We have consistently driven 60 MPH since purchasing this coach and get between 9.0 and 9.2 MPG. I use 9.0 MPG to plan fuel stops. The only difference in our coach and John's is the engine and I think John tows. Weight should be very close as well as frontal area and tires.

As Sarge says, with the speed set at 60 MPH, the torque converter is in lock mode and the transmission drops into 6th gear very nicely. I have tried to use the economy mode on the transmission but am unable to detect ˜any' difference in shift points and no change in MPG. Could it be that on our transmission, the economy mode has been set or defaulted to the same program as the normal mode? I have yet to see any kind of mapping of the shift points from Allison, Freightliner, or Winnebago. Anyone have this?

Staying in the right lane seems to work just fine as concerns the minimum speed limit. If cars or SUVs go whizzing past in the left lane, I just think to myself "I'm glad I'm not paying for their gas". I haven't tried 45 on I95 through DC yet but I imagine it would be scary as "*&^%".

Finally got the tire pressure figured out for the new Michelin Anakee tires on the Bonneville and am now averaging around 52.5 MPG. Wife sees just at 80 MPG on her 250 Rebel. She seems to prefer the little Rebel to the 650 Suzuki S40. It gets a little over 55 MPG. Hard to imagine a 40 cubic inch single cylinder until you ride it, boy does it scoot.

John_Canfield · 08-27-2008, 08:34 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MrTransistor:
Hi Gary & John,

We have consistently driven 60 MPH since purchasing this coach and get between 9.0 and 9.2 MPG. I use 9.0 MPG to plan fuel stops. The only difference in our coach and John's is the engine and I think John tows. Weight should be very close as well as frontal area and tires.

As Sarge says, with the speed set at 60 MPH, the torque converter is in lock mode and the transmission drops into 6th gear very nicely. I have tried to use the economy mode on the transmission but am unable to detect ˜any' difference in shift points and no change in MPG. Could it be that on our transmission, the economy mode has been set or defaulted to the same program as the normal mode? I have yet to see any kind of mapping of the shift points from Allison, Freightliner, or Winnebago. Anyone have this?--snip-- </div></BLOCKQUOTE>Mark - we usually weigh (coach+toad) around 36,500 on the road.

What I remember about the Allison shift modes is the economy mode primarily benefits city stop-and-go driving. With my typical use, I believe the economy mode would make no perceptible difference. When the coach was new, I would go the the effort to put the tranny into economy mode when not highway cruising; after a few months of ownership I didn't bother.

SargeW · 08-27-2008, 09:24 AM

The documentation on my 3000 indicates that the Mode button was good for rolling terrian when staying in a higher gear longer is beneficial, instead of downshifting at a slight incline. It is not recommended when lower gears for more power, like hitting some steep grades may occur.

porscheracer · 08-27-2008, 09:35 AM

I wish I had a Cummins.

From what I understand, the CAT C7 just doesn't get the economy a Cummins ISC does. I know my old Monaco would get 10MPG with no problem - of course it was a 260 ISB, and weighed almost 10K less than the Vectra. The extra 50HP wouldn't hurt my feelings either.

And, like the other posters - I can't tell any difference between normal and "economy" mode on the 3000.