Navistar's new engine?

[tomdent]

Does anyone have any first hand experience with their new maxxforce engine? A friend just went looking at new Monaco's, a 2011 40 footer had a 350 horse, 1160 lb torque engine that gets 12 mpg by recycling the exhaust. From what I have read so far it looks like a good motor, but any input about these engines would be appreciated.

[Wannabe]

I don't have any first hand experience with these engines, but I had a couple of Ford 350's that had the International engines (Navistar). Currently, they use EGR technology instead of DEF which could prove promising in Motorhomes, but they had problems with the 6.0 and 6.4 engines in the Fords-probably one of the reasons Ford designed their own. Some of the problems concerned the EGR valves. It's too soon to know, but I'm just commenting on some past problems.

[moisheh]

Those MPG figures are an urban legend. The smaller front engine Vesta does get good MPG but I dont think a conventional 40 footer can attain that figure. There is a big war going on between Navistar and all the other engine mfrs. as to which pollution method is best. Cummins claims better mpg. The rest of the world does not use the EGR method. Only Navistar. Time will tell who wins.

[Mike Canter]

They used to all use EGR because that was the only way to meet emission standards in the early 2000's. Using EGRs reduced MPG a lot. Then they went to DEF. I think it is pretty amazing that they can say that you can increase MPG by using an EGR. Maybe what they can say is that they can increase MPG using an EGR instead of DEF but you can't say that using an EGR gives you better MPG over an early non EGR motor. I have a engineer friend that works for Cummins backroom R&D and he says they are testing a motor that does not use an EGR or DEF and gets fair MPG.

[rg neumann]

We have Monaco Vesta 32 ft with the MaxForce 7 engine. Have had no problems with engine. We get between 13 & 16 MPG depending on terrain. After 10000 miles have averaged slightly over 13 MPG. Unlikely to get 12 MPG on 40 footer except on level terrain @ speeds of 55 MPG or lower.

[Wannabe]

Quote:

Originally Posted by rg neumann We have Monaco Vesta 32 ft with the MaxForce 7 engine. Have had no problems with engine. We get between 13 & 16 MPG depending on terrain. After 10000 miles have averaged slightly over 13 MPG.

May I assume that you are not towing? Are these mpg figures calculated the old fasioned way or are you using the computer?

[Downsizer]

I'm sure they will have different & larger engines in the 40+ footers..... the MaxxForce Navistar sure beats having to deal with and depend on the Urea System... time will tell on overall performance though.

[Bob (WA0MQE)]

For a small 32-foot motorhome, especially powered by a diesel engine, his mpg of 13 to 16 is not surprising at all. My second coach was 32-foot which was gas powered, weighed 18,000 lbs (not counting toad) and I could easily get between 10 to 12 mpg. Usually 10 while I was towing and up to 12 while not towing.

[jdo]

Have just purchased the 43 DFT and was wondering what kind of mpg I can expect. Anyone having any firsthand knowledge of this unit would be appreciated.

[JDT]

There was a couple parked next to us recently who had an 11 40', four slide Ambassador with the MaxForce engine. He said he is averaging 12.5 mpg. I would love to believe that but I feel good if I get 8.5 mpg on mine with my Cummins.

[Pairajays]

Quote:

Originally Posted by JDT There was a couple parked next to us recently who had an 11 40', four slide Ambassador with the MaxForce engine. He said he is averaging 12.5 mpg. I would love to believe that but I feel good if I get 8.5 mpg on mine with my Cummins.

I have a 40' Beaver with a 425 HP Cat C-12. I travel between Yuma AZ and central Washington state, every year, via I-5. With my Cruise set at 55 MPH, I consistently get 9.5 MPG as indicated by my SilverLeaf. I find it difficult to believe anyone with a similar set up can achieve anything near 12.5 MPG.

Jim E

[deSanford]

I have a 2011 Monaco Cayman that while towing a Mini Cooper and going at least 62 MPH in order to get to 6th gear in overdrive going down hill with a tail wind I might get 8 MPG.

[moisheh]

desanford: Good one. That sounds more like it. Why do people always exagerate their MPG? Do you get extra points if you attain higher mileage?? Unless one does a constant check it is near imposible to have accurate figures due to the design of most fuel tanks. Towing our full size Silverado( 6200 lbs.) we get 7 to 8 in the flat lands and way less in the mountains. If your MPG is going to be a problem then it is time for a new hobby. Considering that the average MH does about 5 to 6000 miles a year does it really matter?

[Sammie]

Quote:

Originally Posted by moisheh desanford: Good one. That sounds more like it. Why do people always exagerate their MPG? Do you get extra points if you attain higher mileage?? Unless one does a constant check it is near imposible to have accurate figures due to the design of most fuel tanks. Towing our full size Silverado( 6200 lbs.) we get 7 to 8 in the flat lands and way less in the mountains. If your MPG is going to be a problem then it is time for a new hobby. Considering that the average MH does about 5 to 6000 miles a year does it really matter?

Back when I had my 1990 Pace Arrow/Chevy, a good friend of mine with the same coach would always brag about how his mileage was so great. It was sooo good that he told me there was times he would need to siphon out some gas along the way.

Sammie