Community Forums

Hit_the_Rhod · 05-05-2015, 07:56 PM

We just purchased a new (to us) 2001 Dutch Star 3891 and we have been crawling all over (and under) it getting a feel for it. One thing that jumped out at me was there is a great big empty space just aft of the stock 100 gallon diesel fuel tank. Right to left it is between the chassis rails, bordered on the port side by the propane tank, and on the starboard side by a storage bay. It is the width of the frame rails (maybe 32") and about the same long and a little less tall.

My question is: Has anyone used that space to install an auxiliary diesel fuel tank? It would seem to me that there is space for about a 50 to 60 gallon fuel tank (assuming a similar installation to the original OEM fuel tank). I envision putting in a vent, a filler neck that would be accessible from the propane tank bay, and a 12 volt diesel fuel transfer pump that is capable of running "dry" without any damage. I would also put a sump drain in the bottom of the tank along with a standpipe to the fuel supply line going to the fuel pump. In use, I would wait until my original is down to about 1/4 full (in order to ensure that I don't over fill the tank and dump fuel, and turn the transfer pump (which would have a led indicator light on the instrument panel next to the transfer pump switch. The pump switch would also have a guard over it to prevent inadvertent activation. Assuming a 11gpm pump, keeping the pump energized for 5 minutes should transfer the entire tank into the OEM fuel tank, bringing it to 3/4 tank or more. That would be handy for trips through the middle of no where, or boondocking trips where generator usage will be more than normal. Any comments? This is not meant to be a discussion on why I think 100 gallons isn't enough! What I'm asking for is whether anyone sees a safety reason not to do it, or a reason why that space is not suitable for a fuel tank. Thanks for viewing!

Mr_D · 05-05-2015, 08:06 PM

I think you'll find that you will be close to or over your maximum front axle weight rating as it sits now and adding more to that wouldn't be good. Our 2002 DSDP on Spartan with a 150 gallon tank was overweight on the front axle by 50#'s if I filled the fuel and propane tanks and that was BEFORE we ever loaded anything onboard or even ourselves.

Dutch Star Don · 05-05-2015, 08:23 PM

No discussion wanted, so bad idea for weight reasons and expenditure vs advantage!

Rotten-Red · 05-05-2015, 09:23 PM

You've gotten good advice from MR D and Dutch Star Don, You'll be getting close to axle weight rating if you have the 12,000# axle. With the 100 gallon tank you have now you can get easily 500 miles and if you push it can get close to 600. But that's not why you called!

If you plan on going ahead with this project there's a much simpler way. You don't need transfer pump, fill pipe, drop pipe for suction line. All you need is a fitting on the front side of your aux. near the bottom, and a vent pipe at the top. However you'll have to have a fitting put into your existing tank on the back side near the bottom to match up with the fitting on your aux. tank. Then you put a fuel line between the two tanks. You will need to use a large enough hose so the fuel runs across fast enough when your fueling to stay equalized between the tanks. Then run a vent hose from the aux. tank to tee into your existing vent hose. When you fill your original tank the fuel will crossover into your aux. tank. As you drive the fuel will crossover to the main tank automatically.

This is the way all semi tractors with tanks on both sides operate. Only one tank has the drop pipe and fuel gauge and return lines. The other tank is just a dummy tank with vent and crossover line fittings. The crossover line keeps the fuel equalized between both tanks. However both tanks have fill openings on top, but that's just for the convenience of fast filling from both sides at the same time.

You're looking at big expense and lots of work for very little benefit. But that's your decision if it's worth it to you.

Hit_the_Rhod · 05-06-2015, 11:35 AM

Great information all! That's why I asked this group, I had not even considered the weight on the front axle issue. That alone is a deal breaker! Now I'll have to come up with something else to spend money I don't have on! Thanks so much for the replies.

JFXG · 05-06-2015, 09:29 PM

My '02 DS 4090 has the 150 gal tank and the 12K Lb front axle. First time I had it weighed loaded, the front end weighed in at 11980. No joke! There's your limitation.

Mr_D · 05-06-2015, 09:49 PM

Quote:

Originally Posted by JFXG

My '02 DS 4090 has the 150 gal tank and the 12K Lb front axle. First time I had it weighed loaded, the front end weighed in at 11980. No joke! There's your limitation.

Our 2002 DSDP 4090 was 12,050 if I filled the fuel and propane tanks and BEFORE we ever loaded anything aboard or even got in ourselves.
After some back and forth with Newmar and an inspection at Hendersons, Newmar had me take it to Spartan where they replaced the 12,000# axle with a 14,600# unit. But that still limited my front weight to 13,200#'s due to the tires/wheels. Finally replaced the 275/70's with 305/70's on the front axle and added Alcoa wheels all around. Then of course the tires would hit the body if the suspension was down but I only did that once!
Our CCC at delivery was only 663#'s and ALL of that was on the rear axle.

tednruthy · 05-07-2015, 07:02 AM

On my 2001 DSDP I used this very large space to store my 'blue boy' tank which I seldom used but hated to be without just in case. I used two substantial poly ropes to secure the tank up into the space. If I needed it I crawled under and took it down. I never did need it and even forgot to remove it when I traded to my 2014 coach. The 2014 Ventana has the same space as it also has a 100 G tank. The sace does have a sheet metal baffle on a 45 degree angle to deflect air and road water from just hittling the front side of the storage bay aft of the tank so the space isn't as usable.

Quote:

Originally Posted by Hit_the_Rhod

Great information all! That's why I asked this group, I had not even considered the weight on the front axle issue. That alone is a deal breaker! Now I'll have to come up with something else to spend money I don't have on! Thanks so much for the replies.

Hit_the_Rhod · 05-07-2015, 08:09 PM

Tednruthy,

That's a great ides on the blue tank! I currently have a 42 gallon tank tucked up under the TT that we will be selling. I was going to use it on the Dutch Star, but couldn't figure out where to put it. The PO has a much smaller tank (22 gal?) strapped to the roof but that's so tacky. I'll have to see if the 42 gal will fit there. I've actually never used it on the TT, but you know the deal, as soon as I don't have one, I'll need it. Thanks for the tip!

tom chelbana · 05-07-2015, 09:10 PM

Had an 95 London Aire we added a 50 gallon tank behind the main tank and waited till 1/2 down and refilled main tank. Need to weigh front but one thing you can do is remove big propane tank which we did by going to residential fridge. Put small propane tank in and even using coach 200 days a year the small 5 gallon tank lasted. Love to travel almost 1000 miles before fill up.

jdouglas · 05-08-2015, 06:00 AM

I have added at 50 gal tank to my 2012 ventana 4034. It has worked out great, remember you do not need to fill both up all the time. When full the load will lessen as you drive so you will not be a max weight all the time. I removed both tanks and installed a 2 inch transfer line, both tanks fill at the same time. the fuel gage works the same as it did before. We do not plan our trips, never know where we will be stopping. With the added fuel some of the time we are able to bypass areas of higher fuel prices. Most folks know that fuel prices can vary up to twenty cents from state to state. Look at SC fuel tax verses NC or GA. I just like the peace of mind I get from the extra fuel . The 100 gal only gives you the use of 75 gallons before the Oasis unit is cut off. I hopes this helps, I know that not everyone will agree, but it works great for us.

Rotten-Red · 05-08-2015, 09:41 AM

Quote:

Originally Posted by jdouglas

I have added at 50 gal tank to my 2012 ventana 4034. It has worked out great, remember you do not need to fill both up all the time. When full the load will lessen as you drive so you will not be a max weight all the time. I removed both tanks and installed a 2 inch transfer line, both tanks fill at the same time. the fuel gage works the same as it did before. We do not plan our trips, never know where we will be stopping. With the added fuel some of the time we are able to bypass areas of higher fuel prices. Most folks know that fuel prices can vary up to twenty cents from state to state. Look at SC fuel tax verses NC or GA. I just like the peace of mind I get from the extra fuel . The 100 gal only gives you the use of 75 gallons before the Oasis unit is cut off. I hopes this helps, I know that not everyone will agree, but it works great for us.

It sounds like what you have done is what I described in post #4.

I'm confused about a couple things. You said "remember you do not need to fill both up all the time". Then you said "I removed both tanks and installed a 2 inch transfer line, both tanks fill at the same time".

If they both fill at the same time, how can you not fill both up all the time? Do you have a shut off valve in the transfer line? If so then you could leave the aux. tank empty and only fill and draw from the main 100 gallon tank. The down side of a valve in the transfer line would be each time you wanted to use or not use the aux. tank you would have to crawl under the MH to turn it on or off.

jdouglas · 05-08-2015, 03:01 PM

I do not fill both all the time. They are hooked together with a 2 inch pipe that allows both tanks to fill at one time. No need for a transfer pump. If the fuel gauge is at half full I know I have 75 gallons of fuel instead of the 50 gallons on the 100 gallon tank by its self. You could use a cable operated ball valve between the tanks if you did not want to use the second tank all the time. I own Young`s Fuel Service and if I can use my own fuel it works out better for me. I have also added PROPANE injection to my coach and am fairly pleased with the increased power an fuel economy. The fuel tank I used is the tank that is found on the Freightliner Business Class trucks. I appears to be a perfect fit. Just remember that it is your coach and having it the way you want it what makes it yours.

Mr_D · 05-08-2015, 03:05 PM

Quote:

Originally Posted by Hit_the_Rhod

Tednruthy,

That's a great ides on the blue tank! I currently have a 42 gallon tank tucked up under the TT that we will be selling. I was going to use it on the Dutch Star, but couldn't figure out where to put it. The PO has a much smaller tank (22 gal?) strapped to the roof but that's so tacky. I'll have to see if the 42 gal will fit there. I've actually never used it on the TT, but you know the deal, as soon as I don't have one, I'll need it. Thanks for the tip!

In my 55+ years of RV'ing I've only found I could have used one of the Blue Boys once and that was at home.