dleslie125 wrote: What has surprised me so far is that the 8.1 can't match the 7.6 we got from our Cummins ISC and the 8.3 from the Cat C7 - and the actual GCW's of those were much higher. I can see why GM is going to dump the 8.1 as it is far from fuel efficient.
Aren't you comparing the proverbial "apples to oranges" here? I'm not sure you can compare mpg numbers of diesels vs. gassers as you've done in your statement. And, quite frankly, at the current prices of gas and diesel, the 8.1 would STILL be cheaper to cover the same ground. Yes, the diesels are heavier, but it's been shown here many times that weight is not one of the main issues of fuel economy.
I'm actually fairly impressed with the mileage we get in ours, and I don't think "mileage" is the reason GM will ultimately replace the 8.1L. From what I gather on many posts here, the 8.1L V8 does a tad better than the 6.8L V10 Ford on similar rigs. (This is more easily compared on the class A rigs as it's quite common to have a Ford or Workhorse option.) And you don't know how much it bothers me to have to say that as I'm basically a Ford guy (over GM) in most things. But that 8.1L/Allison combo, in my opinion, still bests what Ford currently offers.
And yes, bucking winds will certainly hurt the numbers. I like the "billboard" analogy. I usually describe is as driving a sailboat down the highway! LOL
~Rick
2005 Georgie Boy 3625 DS on a Workhorse W-22 (Class A)
Rick, Gail, 2 girls (11 & 7), 2 boys (8 & 5), 1 plump Golden Retriever.
2001 Honda Odyssey with Demco Aluminator tow bar & tow plate, SMI Silent Partner brake controller.
dleslie125 wrote: What has surprised me so far is that the 8.1 can't match the 7.6 we got from our Cummins ISC and the 8.3 from the Cat C7 - and the actual GCW's of those were much higher. I can see why GM is going to dump the 8.1 as it is far from fuel efficient.
Aren't you comparing the proverbial "apples to oranges" here? I'm not sure you can compare mpg numbers of diesels vs. gassers as you've done in your statement. And, quite frankly, at the current prices of gas and diesel, the 8.1 would STILL be cheaper to cover the same ground. Yes, the diesels are heavier, but it's been shown here many times that weight is not one of the main issues of fuel economy.
I'm actually fairly impressed with the mileage we get in ours, and I don't think "mileage" is the reason GM will ultimately replace the 8.1L. From what I gather on many posts here, the 8.1L V8 does a tad better than the 6.8L V10 Ford on similar rigs. (This is more easily compared on the class A rigs as it's quite common to have a Ford or Workhorse option.) And you don't know how much it bothers me to have to say that as I'm basically a Ford guy (over GM) in most things. But that 8.1L/Allison combo, in my opinion, still bests what Ford currently offers.
And yes, bucking winds will certainly hurt the numbers. I like the "billboard" analogy. I usually describe is as driving a sailboat down the highway! LOL
~Rick
ABSOLUTELY NOT. Keep in mind the price history for diesel and regular gas. In Canada diesel JUST jumped ahead of regular this year. WHO can say it will stay that way?
Second, the Ford V10 we had was far more efficient in a heavier chassis with a transmission that only had 4 speeds. We regularly got over 9 mpg (US gal) not towing and we've been struggling to get almost 8 not towing with the 8.1. I have to say I just cannot throw such glowing accolades at the 8.1 that you do. I CAN understand why it is going to be discontinued.
What I am hoping is that GM will use the new 4.5L Duramax in a MH C and/or A chassis since 300 hp and 500+ on torque with decent fuel economy would go over very nicely. Also, an exhaust brake - which lets you get 100,000 miles on your service brakes (something that is highly unlikely to be the case with a gasser) would be a big plus.
As to the winds, on our Kodiak forum I mentioned that monitoring the impact was interesting. Usually travelling east of Hwh 401 in Ontario from Windsor you get a good tail wind. Well, two weeks ago we had a very strong head wind. The ScanGauge was constantly sitting at just a bit over 5 mpg. The Allison would not stay in 6th at 60 mph and continually dropped down to 5th. It was very annoying frankly. What we did find interesting though was that when 18+ wheelers passed us (we were driving at 58 to 60 mph) as soon as they got in position to shelter us from the wind the transmission would jump to 6th. The best case was getting a convoy of 18 wheelers with them passing and pulling in front of us. When we had them in front and beside us the tranny would shift to 6th and the ScanGauge would jump to 9 to 10 mpg. I told DW that what I should be doing in joining the convoy and getting in the draft to save fuel. BUT, I have to tell you that we drive MUCH slower with this gasser than we ever did with our two DPs (probably an average of almost 12 mph slower - which makes the fuel consumption comparison even worse for the 8.1) because of the noise factor. The 8.1 is NOT quiet - period. We may put some sound insulation over the access compartment in the cab (yes, there is one of those in a C Class Kodiak). A contact at Allison told me that her husband found the same noise problem with their Class A WInnie that has an 8.1 and he put a sound deadening material over the engine and it made a big improvement. The 8.1 in so noisy that an expensive sound system for our iPod or XM radio is wasted while travelling.
Of course the diesel is not quieter. BUT, when it is so far behind you, you don't hear much from it. You realize the impact distance has when disconnecting the toad from the DP while the engine is still running during the turbo cool-off period (3 to 5 minutes).
Don
Don, Bev & Phil
07 Jayco 32SS on Kodiak May 07 Yahoo Kodiak Group
06 HR Amb 40PLQ ISC 330/950 9/05-5/07
04 Winnie Jrny 39W CAT C7 7/04-9/05)
00 Triple E Commander 5/03-5/04
Toad - 07 Tahoe LTZ 12/06 -
04 Colorado Z71 04- 06
I'm seeing right between 6-7mpg towing 22ft 6500lbs box trailer. My right foot and the wind seem to have the greatest effects on the mileage. I keep the speed a 60 most of the time. I must say, it's much nicer towing with this C than my 29ft mini winnie.
Well I weighed it and as some of you thought it is overweight. Front axle 5255 rear axle 13325 trailer axles 9200 if we figure roughly 10% for tounge weight that means my trailer is closer to 10K This was after filling the fuel tank and with about 3/4 full fresh water and propane, 3 adults and a nine month old. I plan on moving my car to the rear a little and jacking the weight bars up 1 more chain link to put some more weight on the front axle. Probably won't be able to do a lot about being over the GCWR but I think I can move things around to keep from having any one of the axles overloaded. No wonder this thing gets crappy mileage and seems like it could use a bit more power
Mine came in at 17,460, front 5,480, rear 11,980. Full water, fuel, propane, and all our stuff we usually travel with. Only my son and I in the coach. Still leaves me almost 8,000 for towing.
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I'm not sure you can compare mpg numbers of diesels vs. gassers as you've done in your statement. And, quite frankly, at the current prices of gas and diesel, the 8.1 would STILL be cheaper to cover the same ground. Yes, the diesels are heavier, but it's been shown here many times that weight is not one of the main issues of fuel economy. 
This was after filling the fuel tank and with about 3/4 full fresh water and propane, 3 adults and a nine month old. I plan on moving my car to the rear a little and jacking the weight bars up 1 more chain link to put some more weight on the front axle. Probably won't be able to do a lot about being over the GCWR but I think I can move things around to keep from having any one of the axles overloaded. No wonder this thing gets crappy mileage and seems like it could use a bit more power 
