MacGregorSailors.com

Posted: **Sun Jul 08, 2007 10:44 pm**

Before it dissapears into the nexus........
Here is a copy of the expected fuel consumption of the various Nissan/Tohatsu outboards.....From the factory page........ and this even has it for the older 50 hp engines many of us have.

Fuel Flow Rates

Code: Select all

Approximate Fuel Consumption Chart for Nissan/Tohatsu 

4-Stroke 
Model/HP      RPM      GPH    Liters/Hour 
NSF 2        5,000     0.24       .9 
NSF 3.5      5,500     0.4         1.4 
NSF 4        5,000     0.4         1.5 
NSF 5        5,000     0.5         1.7 
NSF 6        5,500     0.5         2 
NSF 8        5,500     0.85        3.2
NSF 9.8      5,500     1.0         3.8
NSF 9.9      5,000     1.1         4
NSF 15       5,500     1.5         5.5
NSF 18       5,500     1.5         5.7 
NSF 25       5,500     2.3         8.7 
NSF 30       5,500     2.6         9.8
 
2-Stroke 
Model/HP      RPM      GPH       Liters/Hour 
NS 2.5      4,500      0.4          1.4 
NS 3.5      4,750      0.5          1.7 
NS 5        5,000      0.7          2.5 
NS 8        5,000      1.1          4.3 
NS 9.8      5,500      1.3          4.9 
NS 9.9      4,900      1.5          5.5 
NS 15       5,500      1.9          7.3 
NS 18       5,500      2.2          8.5
NS 25       5,500      3.3         12.5
NS 30       5,500      3.4         13
 
NS 40C      5,500      4.5         17
NS 40D      5,350      4.5         17
NS 50D      5,500      5.2         21
NS 60B      5,250      6.3         24 
NS 70A      5,250      7.6         29
NS 70B      5,500      7.7         28
NS 90       5,250      9.3         36
NS 120      5,450     13.2         50
NS 140      5,450     15.3         58

TLDI
Model/HP      RPM     GPH     Liters/Hour
NSD 40       5,500     4           15.2 
NSD 50       5,500     5           19 
NSD 70       5,500     6.4         24.2 
NSD 90       5,500     8.5         32 
NSD 115      5,500    12           45.5

Note: The NS 50D numbers are different than the best I have been able to get.

[mod]ModEdit: Correct table spacing (code), moving to P&T ~fc[/mod]

Posted: **Mon Jul 09, 2007 3:14 pm**

In my own experience, the numbers for the NS50D seem correct.

In terms of miles per gallon, I've seen the following:

High speed mode at 16.5 knots and 5000 RPM = 3.3 MPG

Near hull speed at 5 knots and 2000 RPM = 6.2 MPG

~~~~~~~~~_/)~~~~~~~~~~
Rich Plumb "Plumb Crazy"
26X, Covington WA

Posted: **Mon Jul 09, 2007 5:28 pm**

my last check was 5100 and 5.9 gph........

Hmm,,, must be running a bit rich.....

Posted: **Tue Jul 17, 2007 4:54 am**

How curious ... the 40 and 50 show scant improvement with TLDI injection.

TLDI's fuel economy advantage seems to be only about 10%, even for the larger models. By contrast, the advantage of the conventional 4-strokes over the 2-strokes is significant.

Posted: **Tue Jul 17, 2007 7:43 am**

To some degree.......

but their original carbed large two strokes were pretty miserly. My biggest problem with them has always been gunking up the small idling ports........ and having to use fuel cleaner for at least 3 tanks 50 gallons to get squeaky clean.

I have always disliked the little on engine fuel filter that nissan uses, since I feel it is too small. It only took one tank (18 gallon) to block it up. necessitating 2 on the water cleanings for the trip back from BC.

Posted: **Tue Jul 17, 2007 8:23 am**

My Tohatsu 6HP single lung is a fuel sipper. I've not done enough continuous motoring to monitor its consumption but I get 5.5k @ just over 1/2-3/4 throttle. My seat of the pants was that I was using 1/3 gallon/hr. That gives me 16.5kmiles/gallon.

From the consumption curve it looks like I should be doing even better (maybe not). I'll have to monitor it on a long trip and see what we get. Either way it gets better gas mileage than my truck does.

MacGregorSailors.com

Nissan Outboard fuel consumption from factory info

Nissan Outboard fuel consumption from factory info