Community Forums

brobox · 02-24-2015, 06:47 AM

I have not had good mileage since we picked our coach up from Entegra....5.6-6.2 and let it slide for the first 5,000 miles. On the 259 mile trip to Tampa cruise set at 68 up and back... 5.4 MPG that's with pen and paper, computer said 7.1. I now have 5,600 miles on the engine.

I called Spartan and they also felt it might be a computer glitch with Cummins. We checked my engine serial # and I do have the new 2013 economy flash.
Has anyone else have this problem on a new engine? If so, was it corrected by a trip to Cummins?

Thornhammer · 02-24-2015, 07:02 AM

have to tried your MPG going slower like 60 lots of motors get better gas mileage going slower even the 18 wheelers

brobox · 02-24-2015, 07:31 AM

Quote:

Originally Posted by Thornhammer

have to tried your MPG going slower like 60 lots of motors get better gas mileage going slower even the 18 wheelers

I know I can get better millage if I drove slow and tied up traffic. I go with the right hand lane flow of traffic and on this trip did 68 MPH for test purposes. That is also the speed I normally drive 66-68 MPH. I am not trying to get 10 MPG, just wanted to see if any others had low millage at break in or needed a computer flash with a new engine.

LVRVLUVR · 02-24-2015, 07:45 AM

Quote:

Originally Posted by brobox

I have not had good mileage since we picked our coach up from Entegra....5.6-6.2 and let it slide for the first 5,000 miles. On the 259 mile trip to Tampa cruise set at 68 up and back... 5.4 MPG that's with pen and paper, computer said 7.1. I now have 5,600 miles on the engine.

I called Spartan and they also felt it might be a computer glitch with Cummins. We checked my engine serial # and I do have the new 2013 economy flash.
Has anyone else have this problem on a new engine? If so, was it corrected by a trip to Cummins?

this sounds like one of my stories... everytime I get a pusher,,,, low milage... except for the little 330 hp I have now... I always get 5 or 6 and ever one else gets 10 or 12..

some times I wonder

DSL417 · 02-24-2015, 07:46 AM

With my 13 Anthem, I noticed initially that my mileage dropped below 6 mpg when my speed increased above 65. I also saw the mileage you are experiencing with any kind of cross wind (as well as expected with headwinds). Don't understand the cross wind results, but it was was it was. The mileage computer's have all been suspect...multiple brands from what I've read on here. Then there are 13 and 14 Aspire owners that claim as high as 10 mpg. I only saw that once coming across the flats in the center of the country at 60 mph. Over a year and a half I rarely saw better than around 6.4 mpg with the ISL. That was all the way to 23000 when I traded up.

My CS gets better milage than the 450SL even though heavier and larger engine. Think it is directly related to the lower rpm at higher torque of the ISX.

dusty56 · 02-24-2015, 07:58 AM

Brobox that mileage does seam low. But those few days in Tampa you had the AH on?

Remember the trans develops memory on driving experiences. You had many drivers with different driving habits. You can flash the computer and that will default to factory settings, but you really just need to drive it. At this point I wouldn't worry to much about it. Going down the road you also have to take into consideration if you had the front ac on. That compressor on the motor will take away mileage. If your alternator was working hard charging batteries, head winds etc...

You also had the rear end worked on and quite gears installed. I assume they were the standard 488 just saying so you are comparing apples to apples.

I told you the other day, you need to drive it to key west stay the night, the next day drive it to Jacksonville stay the night, the next day drive it home. A good 1500 mile trip will shake out the cobwebs. LOL

Crippsfl · 02-24-2015, 08:02 AM

Can't speak about the 450 but I can give you my experience with the 600. With 7000 miles under my belt including driving across the Appalachians and using the Aquahot regularly, averaged about 6.5 mpg. Computer reading 6.7 mpg but, that would seem about right considering the Aquahot use. Not enough generator use to matter.

Usually cruise at 65 - 68 mph when on freeways. A fair amount, say 1500 miles, was on secondary roads with plenty of stop and go traffic. All that said, I am extremely pleased with the mileage and performance.

I just gotta remember to quit leaving rubber and popping wheelies when the traffic lights change.

99phantoms · 02-24-2015, 08:05 AM

Quote:

Originally Posted by brobox

... 5.4 MPG that's with pen and paper, ...

Question... when you're calculating MPG's using pen & paper, how do you factor out of the equation the fuel used by the generator?

loisjop · 02-24-2015, 08:14 AM

Chuck, since new I have never seen less than 7mpg and that was with a head wind when going to Ca. Normally we run a consistent 8-8.3. That's figuring it with pencil and paper. Our dash computer always reads about .5 high.
I usually drive around 65 +or- a couple. I don't track the DEF real close, but I think we get about 350-400 mpg on it. We rarely use the generator or aqua hot on diesel. Noel

TXBart · 02-24-2015, 09:25 AM

I am averaging 7.2 mpg for 12,630 miles calculated in a spreadsheet. I have gotten as low as 6.1 and as high as 8.4 for a tank of fuel. I don't adjust for on-the-road generator use which at .5-.7 gph should be negligible. I think summertime Aquahot use is lost in the noise also. Wintertime Aquahot use is a different story; that has yielded mpg of 3.7-4.1 for 2-3 weeks in The cold!

I set my cruise at 62-63 and find I am not the slowest traffic on the road. I prefer not to be in the fast lane when in the MH.

At an average fuel price of $4.04/gal my cost/mile for fuel is $0.59.

hawgguy · 02-24-2015, 09:42 AM

Chuck - how is the performance? Is it in line with what it should be? Have you climbed any hills? What about on-ramp acceleration or passing? If the performance seems OK, I would be patient and keep calculating.

brobox · 02-24-2015, 09:54 AM

Dave, thank you for the honest report on the ISL. I will take the advise of you and Mike with a few more trips. I guess from real reports MPG in the 6's is going to be the norm. I did have a strong cross wind going up, but forgot that when I received the sticker shock at the pump when I got home.

tnrzryd · 02-24-2015, 09:54 AM

After 28,000 miles, our lifetime average is 7.6 mpg taking into account generator and aqua hot usage. Typically drive 65 unless we are in California, where I stick the cruise on 59. Being out west, we do a lot of hilly/mountain driving. Very pleased with what we get.

brobox · 02-24-2015, 10:00 AM

Quote:

Originally Posted by 99phantoms

Question... when you're calculating MPG's using pen & paper, how do you factor out of the equation the fuel used by the generator?

I didn't have to, I didn't turn it on. But when I have I figure 1/2 gal to an hour of use and use the WAG method of figuring that into the millage.

I am not a real stickler on MPG, just was shocked at 5.4 when I have never even been close to 7 yet. I guess I may never see that, hopefully after a few miles......maybe.