Community Forums

clyde1949 · 07-11-2019, 11:08 AM

Im one of those guys that aways fill me tanks after i arrive home.
Coming home from Q i thought i was getting great milage not true the tanks weren't totally full, fuel up to the next and maybe running out but not fuel maybe 95% on the dash gauge, Yes i always open both sides when refusing, is there a secret to filling tank
this is not accurate but going to Q this year i burned lets say 33 gallons going
fuel in Q then Home 25 gallons later i found out even though fuel running out the neck appears to be full but not
so figures something like 7.5 goin and 9 mpg back which is an error.
i do keep a log or all fill up and milage but seems lately cant get tanks totally full
wondering if there is a secret to it.

Gary.Jones · 07-11-2019, 11:22 AM

Clyde

Cant help you on a number of issues but I can point out a couple of factors.

If you notice how the fuel hose runs, the fuel fill is right about the level of the fuel tank which is between the rails of the coach. To get any drop in the fuel fill line, the fuel fill line has to be entering the tank middle of tank or lower. I think. So its not like you are filling the tank up from the top.... I think that is part of the issue.

And, if you remove the other side diesel fuel cap when you fill, IMHO, you are just asking to blow lots of diesel out the other side of the coach when you are filling with a high speed diesel pump fuel pump. I used to take both caps off until I put 5 - 10 gallons out the other side of my coach and all over the pump and the side of my coach once.... I never did it again. If you fill from a puny car diesel pump, you dont get enough flow to be a problem, but I have learned my lesson and I will never take the other cap off when I am filling. If it doesn't fill to the tippy top, I dont worry about it.

And trying to figure mileage from miles traveled to gallons pumped is almost always inaccurate. You probably dont have it, but my coach actually meters fuel used per mile continuously, and that is a far more accurate calculation than the gallons bought and miles traveled. Using that method you will go from 10 mpg to 5.0 mpg with no real change in fuel use. JMO, but what I have observed.

Your ISL 450 is going to get from 7.5 to 7.9 mpg almost all the time.

Gary

Rollin101 · 07-11-2019, 11:23 AM

Quote:

Originally Posted by clyde1949

Im one of those guys that aways fill me tanks after i arrive home.
Coming home from Q i thought i was getting great milage not true the tanks weren't totally full, fuel up to the next and maybe running out but not fuel maybe 95% on the dash gauge, Yes i always open both sides when refusing, is there a secret to filling tank
this is not accurate but going to Q this year i burned lets say 33 gallons going
fuel in Q then Home 25 gallons later i found out even though fuel running out the neck appears to be full but not
so figures something like 7.5 goin and 9 mpg back which is an error.
i do keep a log or all fill up and milage but seems lately cant get tanks totally full
wondering if there is a secret to it.

One big reason you’ll never get them full is the filler goes into side of the tank, close to the top, but still on the side. Taking the cap off the opposite side you’re filling on is dangerous. You will wind up with a large fuel spill some day. I have ask Entegra to move the fuel fill up and forward of the slide outs for 5 years. They finally did it in for the 2020’s and the filler now goes into top of the tank.

Cousin Ed · 07-11-2019, 11:38 AM

You have a 150 gal tank. Why worry about topping off? If you just use the first 100 gal you have traveled 700-800 miles, time for a break!

brobox · 07-11-2019, 11:41 AM

X2 what J.H. said. I have had the same tank fill on 3 coaches. What has worked for me is to very slow fill the last couple of gallons. I look at the gauge and figure I'll take close to 65 gallons, at 60 gallons start listening, you can hear the tank getting fuller, slow the fill down. The last gallon look into the fill port and you will be able to see the fuel. Stop, your full, you can wait a second and see if any air comes out, but it won't take but a 1/4 of a gallon more.

Like others said, do not open the other side fill cap.

MoHoGo · 07-11-2019, 01:58 PM

When fueling I just set the pump to the lowest notch on the nozzle. Slow, but typically always fills to almost the F on the gauge without any spill. Use the extra time to either clean the windshield or do a slow walk around the coach to look things over.

Tom78418 · 07-11-2019, 02:37 PM

First, I totally agree with the replies not to open both sides. The pump nozzle will not sense the the tank is full with the opposite side fill cap off and stay open pouring diesel out the open side.

I typically consider 1/4 tank is time to refuel. We had a diesel tank sender unit issue that even when the tank was full the highest the gauge would show was 7/8 full. Fuel gauges are notoriously inaccurate, but in our case it was unacceptably inaccurate. Staying with the 1/4 tank time to fill, the erroneous sender unit reduced the range we would travel between fill ups. The unit was replaced and the difference immediately noticeable with the first tank fill and the increased range driving on the top 3/4 tank.

clyde1949 · 07-11-2019, 02:43 PM

Quote:

Originally Posted by Cousin Ed

You have a 150 gal tank. Why worry about topping off? If you just use the first 100 gal you have traveled 700-800 miles, time for a break!

I just like to log my milage i keep a complete dairy on my coach and have for over 16 years its fun to look back and see what when . it has nothing to do with fuel range or cost

brobox · 07-11-2019, 02:59 PM

Quote:

Originally Posted by clyde1949

I just like to log my milage i keep a complete dairy on my coach and have for over 16 years its fun to look back and see what when . it has nothing to do with fuel range or cost

I can't do that anymore. When I started RV'ing fuel was under $1.00 a gallon. If I did that now, I would get sick.

My Dad & Mom were full timers. I found Mom's fuel journal when she passed away a few year ago.....I got sick again, 29 cents a gallon. Don't do that to your kids, burn the journal

Tom78418 · 07-12-2019, 06:42 AM

Quote:

Originally Posted by brobox

I can't do that anymore. When I started RV'ing fuel was under $1.00 a gallon. If I did that now, I would get sick.

My Dad & Mom were full timers. I found Mom's fuel journal when she passed away a few year ago.....I got sick again, 29 cents a gallon. Don't do that to your kids, burn the journal

That gave me such a good laugh, it made my day. Thanks. The definition of a good friend is someone who when learning of your passing will go to your house and erase the hard drive. I guess for RVers, that includes burn the fuel journal.

brobox · 07-12-2019, 07:40 AM

Quote:

Originally Posted by Tom78418

That gave me such a good laugh, it made my day. Thanks. The definition of a good friend is someone who when learning of your passing will go to your house and erase the hard drive. I guess for RVers, that includes burn the fuel journal.

On the flip side, a few years ago Mom gave me their 1969 Travel Journal up the east coast with all their stops and RV parks all the way from FL to Bar Harbor Maine. We planned our summers trip, staying at every RV park still in business and touring every destination they had in the journal and following the same highways, not many Interstate in 1969 like there is today. Many tears were shed that summer knowing I stood in some of the same spots, such as the tower at the tip of Cape Cod, that my Dad had before his passing in 1974. In all the years of RV'ing that is a trip we have never forgotten.

I still have that journal, but did throw the fuel journal away.

The Driver · 07-12-2019, 09:05 AM

At fuel pumps, I press my Hadley air level buttons so I can get a more consistent fillup in a level tank. Cornerstones can do that.

DoggieDaddy · 07-12-2019, 12:07 PM

I will repost this. Diesel fuel foams. It is impossible to get a full tank. It may show full but after the foam settles it won't be. Trying to track your fuel mileage by tank fills is futile.

Solo_RV_Guy · 07-12-2019, 12:28 PM

Quote:

Originally Posted by clyde1949

I just like to log my milage i keep a complete dairy on my coach and have for over 16 years its fun to look back and see what when . it has nothing to do with fuel range or cost

Hmmm. Milking machine? Check!

Holsteins? Check!

Fresh cream for coffee and whole milk for the kids? Check!

So how many head of cattle fit in your coach? In my short Class C, I'd probably have to limit things to dairy goats...