4 Stroke Fuel Economy vs 2 Strokers

[tj309]

I am looking to repower my 18' Hydrodyne with twins and since I am a Merc guy I am looking at a pair of 150XS Optimaxes or a pair of Verados. I have a 225XS on one of my other boats and fuel economy is ok, and I have a 115 4 stroke on my pontoon boat which despite the inefficient hull design gets great mileage and is quiet.

Powerboat Reports did a shootout with 6 150's and my 2 candidates were in there but I have not been able to locate this report.

Bottom line - how much better is a Verado than a modern 2 stroke in fuel consumption?

Thanks in advance - TJ

[perfmarine1]

I think either motor is to heavy for a twin 18' boat. The 150 verado 510lbs,the150 opti 431lbs and up for more HP. I would look for a pair of EFI motors,or carb and save a lot of weight. The 150HP evinrude 418lbs. The merc motors with chrome or nickasil blocks I think are around 360lbs?

[Rudeman89]

In my opinion a 2 stroke will always be better then a 4 stroke. If you are looking to get a 150 four stroke you are going to sacrifice hp and weight. Also of the DI 2 strokes the optimax is a little better on fuel then the Etec. The new DI 2 strokes are better on fuel then the four strokes at certain speeds not quite sure which speed because every boat is different. If you are looking for speed do yourself a favor and get the 2 stroke.

[imq707s]

I saw an article a few years ago in some bassboat magazine where they did a shootout between some 200hp 4strokes, and a 200hp Optimax. The 2-stroke optimax ran faster top end, had better acceleration, and got better fuel economy than the verado.

[tj309]

Good info - keep it coming and thanks. I am primarily interested in fuel economy and quietness. Ass heavy boats do not present a problem for me as I have overpowered many boats just like everyone else in this forum.

[Rudeman89]

If I were going to buy any 150hp engine on the market today my first choice would be the 150HO Etec next would be the Optimax. 4 Strokes just don't have the balls a 2 Stroke does. Plus we will see what happens to the 4 strokes in the coming years because of EPA regulations they are having A LOT of problems with them. The Etec's will survive the upcoming changes.

[perfmarine1]

Good info - keep it coming and thanks. I am primarily interested in fuel economy and quietness. Ass heavy boats do not present a problem for me as I have overpowered many boats just like everyone else in this forum.

Well I was thinking from a water skiers point. That is a water ski boat? A ass heavy ski boat leaves a big hole in the water where it took off,when a barefooter hits that hole, during a deep water start,it is not fun. I have experinced it. That is why a Mastercraft puts the motor in the center of boat. Now if you have a boom it is not a issue,but then thats realy not barefooting is it.

[service860]

My take from running the motors on twins. I would take the 4 strokes. They idle and cruise quieter and have more control that the 2 stroke in that range. Unless u are looking for all out top end then the 2 stroke wins in speed and fuel. The 4 does get louder a wfo, but is alot quieter at 5k on down. jmho. Merc told me the other day they are releasing a new 150 4stroke this fall. 3.0l inline 4 naturally aspirated. mech sift and throttle. supposed to be lightest in class.

[sosmerc]

Merc needs a competitive 4 stroke to fill the gap between the F115 and the Verado 150.
I like the idea of a simple mech shift, normally aspirated 125, 135/140/150 fourstroke. I hope they can do it, and do it right. (they seriously need a much better standard control box for these engines...currently the shift quality is, well,.......shi__ty)

[engineermike]

"Trailer Boats" stated that 4-strokes will do way better than tranditional 2-strokes on fuel, wherease DI 2-strokes will do slightly better than 4-strokes. They've done quite a bit of fuel efficiency testings, so I believe them.

[xsflight]

Think about all the hardware the 4 strokers are turning, camshafts, valves, springs, they use up energy AND add much weight which requires more energy again. D.I. 2 strokes benefit from the ability to produce a stratified charge near the plug-a fuel cloud surrounded by air, which provides more complete combustion than a sequentially injected homogenized charge 4 stroke can. As well, 2 strokes have lower thermodynamic losses under part throttle conditions than 4 strokes.

[Toffen]

Hi!

I have a 350 sci on my Phantom 25 (1985 model straight V, no noth) and I get 4,6 mpg at 4,000 rpms. At 3,500 rpms I get even better milage. A new world to me

Cheeers, Toffen

[imq707s]

The best I have got out of my Vegas XT with the 3.0 Looper and 27 SRX prop has been 3.5 MPG cruising at a constant 49mph at 4000rpms. The boat is mostly out of the water, and the RPM's are not that high. If I go slower, I actually get much less MPG....around 2.5 or so, I think it's mostly because the boat is plowing water...and the prop start to slip a lot.

Does anyone know what a typical 21foot bowrider with a 305 or 350 V8 gets? My friends have a 18' Fourwinns bowrider with a 4.6 Vortec V6....and they can cruise around all weekend and barely use any gas.....I wish I could do that!

[hsbob]

i have a voyager [open bow vegas] with the full smartcraft guage set. i have gotten as high as 7.4 mpg using a 200xs merc. with your boat the 200xs or the 175xs would be worth consideration.

[VELOCITY 3.6GT]

Go with a two stroke if you want a good hole shot, top end and fuel economy. Hanging a heavy four stroke on the boat will change how the boat handles. I personally would go with an e-tec and then a merc . To give you an idea on two stroke efficiency I run a 22 velocity with an e-tec 225 h.o. and consistently average 6-7 mpg with playing and cruising figured in. Also as Rudeman put it the e-tec will meet more stringent epa regulations. As with any two stroke make sure you run good gas and atleast a semi-synthetic oil for long life. I think four strokes are fine for pontoon boats but not for the performance minded. Do yourself a favor and go for a ride with someone with an etec or an opti then ride in a four stroke boat and make up your mind I think you will agree with the comments..... Go 2-stroke.