The Sprinter surely gets great fuel economy, a 33%-50% increase compared to the E350/V10. There are two very strong reasons to get a Sprinter.
1) The house built on top of it is exactly what you are looking for.
2) Your plan is to drive 150,000 during your ownership so that the improvement in fuel economy outweighs the increase in cost associated with purchase and maintenance.
Below is a piece taken from another post of mine.
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If considering a current-day “small” class B+ or C motor home, here is a comparison between the two current main chassis contenders, the Sprinter with the V6 diesel engine and the Ford E350 with the V10 gasoline engine.
Advantages Of The Mercedes Sprinter With Diesel Engine- Offers a 35%-50% improvement in fuel economy over the Ford-V10, when both are loaded and driven identically.
- More ergonomic driver compartment with more leg room.
- Comfort continues with a car-like feel & quiet ride.
- A grander view out the windshield
- Made by Mercedes which people are attracted to.
Advantages Of The Ford E350 with V10 Engine- Given identical motor homes both brand and model, the Ford is around $13,000 MSRP cheaper
- The Ford V10 engine has 50% more horse power and torque
- The Ford E350 chassis handles 1430 pounds more weight.
- The E350 is able to tow a heavier load.
- The E350 rear axle is significantly wider which translates to better stability.
- In most places traveled, gasoline costs less than diesel fuel
- The Sprinter diesel has limited mechanical service shops around North America
- The Sprinter diesel is typically outfitted with a propane generator. Propane is a critical fuel for RV operations, and generally needs to be rationed when dry camping.
- This Next Point Is Debatable But Still Worth Noting....The V6 Sprinter diesel engine is not allowed to idle for extended periods. This limitation is detrimental when you need a/c but there are generator restrictions, you are low on propane, or you have a mechanical failure with the generator or roof a/c. The Ford offers a great backup system. The V10 can safely idle for hours on end, heating, cooling, and battery charging, all valuable if you have a baby, pets, or health/respiratory issues.
You decide what your priorities are, and pick the appropriate chassis. There are some really sweet motor homes being built exclusively on the Sprinter chassis, such as the
Winnebago Navion and View. Others like
Phoenix USA build their model
2350 and
2400 on both the Sprinter and Ford E350. They will even build it on the heaviest duty E450 upon request for a nominal fee. People who request an E450 for a small motor home, tow heavier things like for example, a multi-horse trailer. You can even special order a
E350 & E450 4x4.
There is so much cool stuff offered in recent years on the Sprinter and most recently on the new Ford Transit.
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Many people buy a motor home and live in it "parked" much more than they drive it. For those people, the E350 would be the more economical choice. Some people put on many miles, for example following ball clubs around the country. The Sprinter would be ideal for the piles-of-miles.