420 DA Thread

GAS vs DIESEL FUEL COST

I know on this forum there is an endless debate on the merits of gas vs diesel. My 2005 420 Sundancer has Twin 8.1 Horizon gas engines - which probably puts me in the minority for this particular boat - as it seems like 60-70% of the members of this 420/440 thread have Cummins diesels.

One of the things I think is missing is some facts around total cost of ownership for maintenance and fuel for diesels vs gas engines. We know that Diesels have a higher resale value than gas - I thought it would be interesting to see some facts on fuel cost / burn between the two.

I submit myself as the guinea pig for gas engines.

Here are some facts about my gas engine fuel burn test:
  • It was just me in the boat with moderate seas out in Santa Monica Bay.
  • I had to stop the test at 18 knots because of these moderate seas washing over the bow of the boat.
  • My speed measurements are not perfect because I changed directions a few times vs the swell - but they do give a general idea of fuel burn vs speed.
  • I chose to generally measure in 200RPM increments.
  • The fuel cost is based on the cost at the one (and only) fuel dock in Marina del Rey. They give a quantity discount - and I took on over 200 gallons - so my final fuel cost was ~$4.988 / gal.
  • I included total fuel cost vs time for a 30NM trip. This distance is relevant to me as this is the distance between Marina del Rey and Two Harbors on Catalina Island.
  • I took a pic of fuel costs at the marina for August 18, 2018. I captured in the pic both the diesel and gas costs. I know these costs vary by region due to taxes, etc.
Here is my chart of fuel burn vs speed. Fuel burn is courtesy of the engine monitor and speed from the Raymarine MFD:

Screen Shot 2018-09-03 at 12.15.16 PM.png


And here are the costs for both diesel and gas fuel at my marina (as of Aug 18):
Screen Shot 2018-09-03 at 12.17.39 PM.png


My ask is that some of the folks on this thread with Cummins diesels could do a similar speed vs burn test. For comparison purposes use diesel fuel cost of $4.419 per gallon (and/or also note at your marina both the diesel cost as well as the gas cost).

I think this would help provide some quantitative data for people looking to buy 42/44 Sundancers and seeing a significant price distance for gas vs diesel boats.
 

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hynespa, I'll play along.......now with my diesels, I don't have real-time fuel consumption, so what I use in my own fuel logs is the factory fuel burn figures. For the life of me I can't lay my hands on it at the moment, but I recorded the two main vaules in my fuel logs. I primarily use two values:

800 rpm: 1.2 gph per engine. This is a bit higher than idle, but it is my assumed burn rate at idle.
2200 rpm: 13.6 gph per engine. Speed is 25-27 mph (21.7 - 23.5 knts)

I'll use the $4.419 price for 201-400 Gallons.

2200 rpm: 22.6 knts: 27.2 gph: $121/hr: $5.36/NM $160.73/30 NM: 1.3 hours/30 NM (1:18)

The metric that I like to use is Miles per gallon. I am just about 1 mpg. It is the value that I use for planning purposes.

Jaybeaux

PS....I filled up on August 12th and paid $3.099.
 
Just curious...why does everyone do blue?.

Like a bug zapper I would think blue light would attract bugs? I had a couple of big boats near me at the club we were at this weekend that were all red... I know my white lights this weekend attracted the bugs. Does anyone know if/what light color would be best to deter bugs?
 
Anyone have experience with RIB or any inflatable on a 420 DA? Looking for one to deflate and stow w/engine too. Looking for a reasonable way to get around and to shore.
 
Has anyone replaced the CO wired in detectors "fireboy" I have three and all of them have "expired" and i have unplugged them to stop the horrible beeping!! I do have some 110 and a battery one but would like to get these back operational.
thanks
chris
 
GAS vs DIESEL FUEL COST

I know on this forum there is an endless debate on the merits of gas vs diesel. My 2005 420 Sundancer has Twin 8.1 Horizon gas engines - which probably puts me in the minority for this particular boat - as it seems like 60-70% of the members of this 420/440 thread have Cummins diesels.

One of the things I think is missing is some facts around total cost of ownership for maintenance and fuel for diesels vs gas engines. We know that Diesels have a higher resale value than gas - I thought it would be interesting to see some facts on fuel cost / burn between the two.

I submit myself as the guinea pig for gas engines.

Here are some facts about my gas engine fuel burn test:
  • It was just me in the boat with moderate seas out in Santa Monica Bay.
  • I had to stop the test at 18 knots because of these moderate seas washing over the bow of the boat.
  • My speed measurements are not perfect because I changed directions a few times vs the swell - but they do give a general idea of fuel burn vs speed.
  • I chose to generally measure in 200RPM increments.
  • The fuel cost is based on the cost at the one (and only) fuel dock in Marina del Rey. They give a quantity discount - and I took on over 200 gallons - so my final fuel cost was ~$4.988 / gal.
  • I included total fuel cost vs time for a 30NM trip. This distance is relevant to me as this is the distance between Marina del Rey and Two Harbors on Catalina Island.
  • I took a pic of fuel costs at the marina for August 18, 2018. I captured in the pic both the diesel and gas costs. I know these costs vary by region due to taxes, etc.
Here is my chart of fuel burn vs speed. Fuel burn is courtesy of the engine monitor and speed from the Raymarine MFD:

View attachment 59621

And here are the costs for both diesel and gas fuel at my marina (as of Aug 18):
View attachment 59620

My ask is that some of the folks on this thread with Cummins diesels could do a similar speed vs burn test. For comparison purposes use diesel fuel cost of $4.419 per gallon (and/or also note at your marina both the diesel cost as well as the gas cost).

I think this would help provide some quantitative data for people looking to buy 42/44 Sundancers and seeing a significant price distance for gas vs diesel boats.

Thank you for posting this, i also have 8.1's and have semi-regretted my purchase from the beginning but I am finding that for me and my pool the GAS option really isnt that big a deal! Yes I would like the flexibility to travel down stream someday but the upfront higher purchase price and my lack of knowledge on Diesel swayed me.
I really enjoyed the comparison.

Thank you
Chris
 
GAS vs DIESEL FUEL COST

I know on this forum there is an endless debate on the merits of gas vs diesel. My 2005 420 Sundancer has Twin 8.1 Horizon gas engines - which probably puts me in the minority for this particular boat - as it seems like 60-70% of the members of this 420/440 thread have Cummins diesels.

One of the things I think is missing is some facts around total cost of ownership for maintenance and fuel for diesels vs gas engines. We know that Diesels have a higher resale value than gas - I thought it would be interesting to see some facts on fuel cost / burn between the two.

I submit myself as the guinea pig for gas engines.

Here are some facts about my gas engine fuel burn test:
  • It was just me in the boat with moderate seas out in Santa Monica Bay.
  • I had to stop the test at 18 knots because of these moderate seas washing over the bow of the boat.
  • My speed measurements are not perfect because I changed directions a few times vs the swell - but they do give a general idea of fuel burn vs speed.
  • I chose to generally measure in 200RPM increments.
  • The fuel cost is based on the cost at the one (and only) fuel dock in Marina del Rey. They give a quantity discount - and I took on over 200 gallons - so my final fuel cost was ~$4.988 / gal.
  • I included total fuel cost vs time for a 30NM trip. This distance is relevant to me as this is the distance between Marina del Rey and Two Harbors on Catalina Island.
  • I took a pic of fuel costs at the marina for August 18, 2018. I captured in the pic both the diesel and gas costs. I know these costs vary by region due to taxes, etc.
Here is my chart of fuel burn vs speed. Fuel burn is courtesy of the engine monitor and speed from the Raymarine MFD:

View attachment 59621

And here are the costs for both diesel and gas fuel at my marina (as of Aug 18):
View attachment 59620

My ask is that some of the folks on this thread with Cummins diesels could do a similar speed vs burn test. For comparison purposes use diesel fuel cost of $4.419 per gallon (and/or also note at your marina both the diesel cost as well as the gas cost).

I think this would help provide some quantitative data for people looking to buy 42/44 Sundancers and seeing a significant price distance for gas vs diesel boats.
Your 15 knots at I assume is your cruise speed seems very slow..are you sure your numbers are right?...for a diesel comparison my cruise rpm is 2,250 at around 24 knots
 
Last edited:
Has anyone replaced the CO wired in detectors "fireboy" I have three and all of them have "expired" and i have unplugged them to stop the horrible beeping!! I do have some 110 and a battery one but would like to get these back operational.
thanks
chris

I replaced all three of mine year before last. Found them online. I also have 2 independent battery units with readouts. One in the salon and one in the master cabin.
 
Anyone have experience with RIB or any inflatable on a 420 DA? Looking for one to deflate and stow w/engine too. Looking for a reasonable way to get around and to shore.

How often will you use it and how far is shore?

I have a 9'6" Aluminum RIB with a 9.9. We use it nearly every weekend, with myself, wife and daughter it easily planes and runs reasonable fast. Downside is it takes up most of the swim platform and needs a davit to launch and load it. If you go that route I would highly recommend the Hurley H3O davit. Do not get the H2O, it doesn't work on the 420/44.

If just a few times a year and short distances I would get a smaller roll-up and a battery powered outboard. Both can fit in engine compartment.
 
H
hynespa, I'll play along.......now with my diesels, I don't have real-time fuel consumption, so what I use in my own fuel logs is the factory fuel burn figures. For the life of me I can't lay my hands on it at the moment, but I recorded the two main vaules in my fuel logs. I primarily use two values:

800 rpm: 1.2 gph per engine. This is a bit higher than idle, but it is my assumed burn rate at idle.
2200 rpm: 13.6 gph per engine. Speed is 25-27 mph (21.7 - 23.5 knts)

I'll use the $4.419 price for 201-400 Gallons.

2200 rpm: 22.6 knts: 27.2 gph: $121/hr: $5.36/NM $160.73/30 NM: 1.3 hours/30 NM (1:18)

The metric that I like to use is Miles per gallon. I am just about 1 mpg. It is the value that I use for planning purposes.

Jaybeaux

PS....I filled up on August 12th and paid $3.099.


Holy crap!

Here are my numbers with my QSC500s:

2,360rpm
29.5mph
19.5gph each
38.7gph total
85% throttle
75% load


2,250rpm
27.6mph
17.5gph each
35.0gph total
80% throttle
70% load

Just put in $157gal at $2.90/gal.

I think short runs and little use make gas appealing, but if you run a lot and for long diesels will work out to be the better deal.
 
Last edited:
importmonkey.....my aggregate fuel consumption since purchase 2 years ago is a total of 1025.38 gallons Port/ 1001.45 gallons Stbd, on 162.7 Port/161.7 Stbd. Translates to 6.30 gph Port & 6.19 gph Stbd.

You gots all that fancy stuff!
 
Has anyone replaced the CO wired in detectors "fireboy" I have three and all of them have "expired" and i have unplugged them to stop the horrible beeping!! I do have some 110 and a battery one but would like to get these back operational.
thanks
chris

@hynespa did a great write up in this very thread.

http://clubsearay.com/index.php?threads/420-da-thread.1273/page-55#post-987168

I just ordered the new fireboy replacements from west marine.

Also got in two battery operated combo units for the galley and cockpit.

Combination Photoelectric Smoke/Carbon Monoxide Detector for Home, Battery Operated Travel Portable Fire CO Alarm with Sound Warning and Digital Display https://www.amazon.com/dp/B07CWJT89F/ref=cm_sw_r_cp_apa_.RYJBb6Y9MQ8F
 
How often will you use it and how far is shore?

I have a 9'6" Aluminum RIB with a 9.9. We use it nearly every weekend, with myself, wife and daughter it easily planes and runs reasonable fast. Downside is it takes up most of the swim platform and needs a davit to launch and load it. If you go that route I would highly recommend the Hurley H3O davit. Do not get the H2O, it doesn't work on the 420/44.

If just a few times a year and short distances I would get a smaller roll-up and a battery powered outboard. Both can fit in engine compartment.
Many thanks for the response. I am trying to avoid using a permanent mount on the transom and only want it to get around a lagoon or harbor and then a transport to the beach. Thanks again for the insight.
 
@hynespa did a great write up in this very thread.

http://clubsearay.com/index.php?threads/420-da-thread.1273/page-55#post-987168

I just ordered the new fireboy replacements from west marine.

Also got in two battery operated combo units for the galley and cockpit.

Combination Photoelectric Smoke/Carbon Monoxide Detector for Home, Battery Operated Travel Portable Fire CO Alarm with Sound Warning and Digital Display https://www.amazon.com/dp/B07CWJT89F/ref=cm_sw_r_cp_apa_.RYJBb6Y9MQ8F


Thank you so much, I appreciate the info.
chris
 
Many thanks for the response. I am trying to avoid using a permanent mount on the transom and only want it to get around a lagoon or harbor and then a transport to the beach. Thanks again for the insight.
Hey could anyone tell me the difference between a 420 and a 44Da? Im upgrading from my 280 and will be choosing one of these two but I have found that the 420 is a bit cheaper online. Are they the same exact boat? What are the differences??
Nick
 
Many thanks for the response. I am trying to avoid using a permanent mount on the transom and only want it to get around a lagoon or harbor and then a transport to the beach. Thanks again for the insight.
Use HURLEY H30 it is removal and will work great for your set up. They use a battery operated winch. Go with AB 10 VL and a 15 HP motor. Do it once and you will be happy. Ask me how i know????!!!!!
 

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