Which uses less fuel

[stanw909]

A generator ( gas, diesel , propane ) or the new under hood engine generators ? Sorry if this was covered in the posts pertaining to under hood generators but while boondocking on our recent trip in a very hot and humid place I didn't want to run the generator at night because of the noise. My 96 Dodge van has no EGR system so I was ready to just run the engine and use the dash AC but wife would not allow it because of fuel cost involved. Got me wondering if Roadtrek or Advanced RV has provided documentation on the economy of the engine charging systems. My 2800 Onan supposedly uses 1/2 gallon per hour but unsure of what the 5.9 liter V8 would consume.

[markopolo]

I have a bit of info that might help:

In a 2012 email from Sprinter Engineering Support to me they indicated fuel consumption is .4 - . 5 gal. per hour of idling.

My 1997 Chevy at idle, running a 5,200 btu a/c through an inverter, my V8 diesel burns 0.11 Gal/h according to my ScanGauge.

And at idle, running a 5,200 btu a/c through an inverter plus the van dash air on "max air" my V8 diesel burns 0.45 Gal/h according to my ScanGauge.

[Davydd]

It is kind of a moot point with Advanced RV. They are all diesel Sprinters. The engine would not run all night since Mercedes Benz says to not idle for more than two hours without driving on the highway for 40 minutes between idle intervals. Two hours would put nearly 400-500 amps back into the batteries so it most likely would never stay on Autogen that long anyway. Advanced RVs lowest battery amp hour model is 400ah and goes up to 1200ah. You could conceivably run air conditioning all night without running the engine with batteries at 1200ah. I have 800ah battery capacity but this is not something I think I would ever do. First, I doubt I would ever camp in weather requiring air conditioning at night. I like to hope I am smarter than that. Secondly, if it happened I would seek an electrical hookup. Lastly, I did get stuck in 90F weather at night once in Kansas in September. That's why I have a B with a screen on the back doors and the sliding door. I opened the doors. I did that once with our Great West Van. The warmest we have experienced so far in our Advanced RV in over 100 days on the road was 87F during the day. We'll put up to another 60 days on the road this year but heat will be the greater concern.

If one did defy recommendations and ran a Sprinter 8 hours at idle that would be about 4 gallons I guess. Diesel is $2.50/gal. at our nearest service station so that would be $10 while sleeping.

[stanw909]

David since you have experience with older Sprinters, would the same idling rules apply to the pre 2007 vans?

[Davydd]

Originally Posted by stanw909

David since you have experience with older Sprinters, would the same idling rules apply to the pre 2007 vans?

I don't think so. I don't recall any idle warnings or restrictions since they didn't have all the pollution control additions that are causing the maintenance concerns now. Those diesels I think were capable of running forever.

I will say this, I don't think it is smart to sleep with a generator or engine running even if you can do so with the vibration and noise. You may never wake up. Too many things could go wrong.

[wincrasher]

That's why all vans have a CO detector.

[eric1514]

Originally Posted by wincrasher

That's why all vans have a CO detector.

Built by the lowest bidder.

[Davydd]

Originally Posted by eric1514

Built by the lowest bidder.

In China no doubt.

[stanw909]

It appears I have my answer.Engine idling uses less fuel than generator.

[gerrym51]

the idling issues caused by post 2007 sprinters is because of the DPF.

since prior to 2007 no dpf's existed you can idle pre 2007 as much as you want

[stanw909]

Gerry. I was hoping you'd chime in on the subject since this pertains to your Zion. Did Roadtrek tell you what to expect as far as using fuel during idling? Other than possible overheating , the Promaster should have no issues since it has no EGR to clog . Is that correct ?

[gerrym51]

i have had no problem idling that i know of. the longest i did it though was about 30 minutes at one time i do check the heat guage. it always has so far stayed at the 1/2 way point.

as far as i know idling (other than possible heat) is only an issue with diesels and the dpf and egr

[Davydd]

I have to say it again. You have to be some kind of masochist to want to run a generator or idle an engine for more than anything other than to top off your battery or accomplish a task requiring 120VAC for a short period. If I or anyone else is in the wilderness boondocking or in a campground and someone is running either generator or engine overnight within hearing I suspect there would be hell to pay. If you find it necessary then I would ask why you bother to camp in the first place in such a situation? I suppose you could get by with that in a Walmart parking lot next to the diesel semis doing the same.

[stanw909]

I wouldn't dream of idling or using generator in a campground.I also would call that person a sadist for torturing the neighbors,not a masochist.Sometimes when traveling vast distances (we are not retired) when pressed for time we use rest areas,truck stops and yes WalMarts(GASP!!!) to sleep. We have a generator but it makes quite a racket and so I would rather run the much less noisy engine to cool off.This came up one time on our recent 6800 mile trip to North Carolina to take our oldest kids and his new brides belongings to Chapel Hill N.C. in a Uhaul.As long as we were there we did some sight seeing and had a tough night of very high humidity and heat coupled with no plugging in at KMart lot.I ran the genny and roof air about 15 minutes until we got cool,kept the van shut up against the hot humid air,slept a few hours til it started heating up again(had wife alarm to tell me it was time) and repeated process. If at a rest area near truckers or truck stop,I would have just run the generator full time.This all got me wondering about the new under hood generation that has been discussed here extensively but with no mention of fuel consumption.

[stanw909]

Gerry.If I may ask one more time.What does Roadtrek say about fuel use and idling time? Do they have an official rule/warranty stance.I thought you got a gasser.My mistake.

[Davydd]

Gerrym51 has a gas engine Zion with the second alternator Roadtrek likes to call a generator. I would think the warranty issues would be with RAM not Roadtrek since it is an engine issue.

I can tell you this. A Sprinter diesel is just as noisy in decibels outside the van as the Onan generator. If there is much difference it would only be splitting hairs or the type of sound. I think both are a bit annoying.

There are always exceptions Stan in like what you mentioned but if you are basing a buying decision on exceptions like you cited and then suffering through other disadvantages 95% of the rest of the time then it is not smart. I will say though, I think any B with more than 200ah of battery power or lithium ion batteries would be better suited to have a second engine alternator than an Onan generator for a multitude of reasons. I've had Bs both ways and I think the future is speaking alternator. That's my opinion of course.

[booster]

The gassers are a lot quieter, in general. On many, if you didn't here the starter run to start them, you would not know they were running from an adjacent campsite. Of course, that does not give an excuse to be rude or break the rules.

Were the fuel use numbers everyone had for Sprinter idling based on running the engine alone or with a generator at whatever load? If it is engine alone, you would see quite a bit more fuel usage. If and Onan uses .5 gal per hour, I would expect you to be adding maybe .2 gal per hour to the Sprinter, or gas model, compared to unloaded.

[gerrym51]

I have a gasoline promaster. roadtrek has not said anything about idling with the engine generator(alternator)

[stanw909]

Interesting.