ontheplane
Well-Known Member
I know these diesel outboards aren't gaining much traction in the leisure market yet - but I wonder why.
OXE Diesel - Worlds leading outboard diesel engines
The World's Most Powerful Diesel Outboard Motor - Cox Marine
I think cost is the issue (What does a 300HP petrol outboard cost for example?) - However I am surprised that those boats that would have had a Diesel sterndrive in the "old days" haven't bought into them.
I know £40,000 is a lot for 300 hp - but compared to a D4-320 inboard + DP Sterndrive for example, is the cost that much more?
The makers claim (well they would wouldn't they) that as commercially rated motors they have a much longer service life - and fuel consumption around 50% (one review I saw was that at 3950 rpm and 25knts it was burning 5.9lph
Really surprised these aren't getting popular - the OXE especially as they have a range from 125-300hp whereas the COX is only a 300HP motor.
When I see the cost of a typical 40' boat now with twin 300 outboards it makes my eyes water - an extra £20k would barely be noticed, especially as I would suspect that the resale would be much higher given it is a "best of both worlds" solution. Weight isn't too bad - 350KG for the OXE which isn't THAT much more than a 300HP Petrol engine - and actually the torque being SO much higher, I suspect you'd get similar performance to a 350 or even 400HP petrol outboard in terms of cruising even if not pure top-end.
So why aren't we seeing these engines entering the leisure market.
If (and it's a huge if to be fair) I could afford a bit 30-40' boat, new with outboards, I'd want these not petrol on the back for all the range and other issues not just the massive fuel saving.
So to compare a OXE 300 HP to the Yamaha 350 hp
Note, I've had to guess the Yam torque as the website doesn't quote it - so I've just worked on the peak power and divided by the speed - the reality is the torque peak may well be higher at a lower speed.....
To me that OXE is a winning engine - especially with that torque and fuel burn if you have a heavy boat and top speed isn't the be all and end all.
At cruise I expect the Yam would burn 60 ish lph and if you look in their "brochure" - at 2500 rpm it looks to be well under 30 on the OXE - so that gives double the cruise range from a tank, plus cheaper fuel plus (perhaps) increased resale?
OXE Diesel - Worlds leading outboard diesel engines
The World's Most Powerful Diesel Outboard Motor - Cox Marine
I think cost is the issue (What does a 300HP petrol outboard cost for example?) - However I am surprised that those boats that would have had a Diesel sterndrive in the "old days" haven't bought into them.
I know £40,000 is a lot for 300 hp - but compared to a D4-320 inboard + DP Sterndrive for example, is the cost that much more?
The makers claim (well they would wouldn't they) that as commercially rated motors they have a much longer service life - and fuel consumption around 50% (one review I saw was that at 3950 rpm and 25knts it was burning 5.9lph
Really surprised these aren't getting popular - the OXE especially as they have a range from 125-300hp whereas the COX is only a 300HP motor.
When I see the cost of a typical 40' boat now with twin 300 outboards it makes my eyes water - an extra £20k would barely be noticed, especially as I would suspect that the resale would be much higher given it is a "best of both worlds" solution. Weight isn't too bad - 350KG for the OXE which isn't THAT much more than a 300HP Petrol engine - and actually the torque being SO much higher, I suspect you'd get similar performance to a 350 or even 400HP petrol outboard in terms of cruising even if not pure top-end.
So why aren't we seeing these engines entering the leisure market.
If (and it's a huge if to be fair) I could afford a bit 30-40' boat, new with outboards, I'd want these not petrol on the back for all the range and other issues not just the massive fuel saving.
So to compare a OXE 300 HP to the Yamaha 350 hp
Note, I've had to guess the Yam torque as the website doesn't quote it - so I've just worked on the peak power and divided by the speed - the reality is the torque peak may well be higher at a lower speed.....
| Yamaha 350 | OXE 300 | |
| Power | 350 | 300 |
| Torque | 334 Lb/ft @ 5500 rpm 452 NM | 680NM @ 1750 rpm |
| Weight | 346kg | 395kg |
| Alternator output | 50A | 180A |
| Service Interval | ? not sure | 200hrs minor 800hrs major |
| Fuel Burn WOT | 129lph | 70? |
At cruise I expect the Yam would burn 60 ish lph and if you look in their "brochure" - at 2500 rpm it looks to be well under 30 on the OXE - so that gives double the cruise range from a tank, plus cheaper fuel plus (perhaps) increased resale?
