Since our budget doesn’t allow a proper engine shootout, where we would ideally take 3 matching boats and power them with the latest 150 HP outboards to see how they compare in every performance category; we’re going to cheat. Outboard engine manufacturers post performance bulletins for their models, and you can often find the same boat across the tests with different engines. Another cool thing is looking at the same manufacturers engine on the same boat but in a different horsepower; to see if it’s worth it getting a 175 over a 150 for example. I have compiled some tests for the 150 HP range, and a few with 175 HP outboards just for comparison. The last test looks at all three on the same boat, the first two are two out of three on the same boat.
Since we can’t test ourselves, it will be interesting to see the different setups, different props and how fast some of these boats are going. Naturally, all the boats are bass boats, the closest thing to performance boats in the mainstream world. Let’s look at the Yamaha 150 VMAX SHO, Evinrude G2 150 HO, and Mercury 150 Pro XS.
Yamaha 150 SHO
First up, the Yamaha 150 SHO. This engine was introduced in 2012 and was benchmarked with the outgoing 150 HDPI and exceeded it in most performance measures, according to Yamaha. The 2.8 4 cyl is actually based off the F200, which was introduced at the same time and not the F150 2.7L. A slightly lighter swivel bracket, smaller throttle body and a tuned exhaust differentiate it from the F200. The Yamaha is an excellent repower engine.
Let’s see some numbers on a Bass Cat Sabre, an 18’1” bass boat weighing in at 1275 lbs. Test had the engines ventilation plate 6” above the bottom, 6” manual jack plate, 3 batteries, 28 gallons of fuel and a trolling motor. With a Yamaha Pro Series™ prop: 14 1/2 x 23, the Bass Cat hit 62 at 6050 RPM. That’s pretty good given the weight and equipment. The theoretical slip is 5.9%. You could probably lighten that boat up a bit, raise the engine and move to a 24” pitch and get a little more out of it. But, let’s see what a 175 SHO does on the same boat. The 175 is the same engine, tuned for 175+ HP and has a 1.86:1 gear ratio as opposed to the 2:1 on the 150.
The 175 was setup similarly, only with a 8” jack plate, ventilation plate 5.25 above the pad (I think prop shaft to pad is a little better way to measure) and it got 68 at 6100 RPM. This was achieved with a SHO prop, 15 ⅛ by 23” pitch. That’s a pretty big wheel for a lower HP engine. For that, the theoretical slip is 4.8%. These are the reported numbers too, so I can’t verify anything. The 150 was mounted ¾” higher with 2” less setback. Both engines are probably well above their listed HP rating. All things being equal, 6 MPH for 25 more HP is pretty solid. Could the 175 be raised to match the 150, and run a 24” or even 25” same 14 ½ prop to gain a couple MPH, yes. These props are very different, so there is no telling how much faster a different one could be. I have a feeling 70 MPH is in the cards for the Yamaha 175 SHO fairly easily.
What doesn’t appear to make sense above, is the more powerful 175 with taller gears, running the same pitch? Let’s take a look. The larger diameter prop has a large effect, and in general, increasing diameter that much is like adding pitch. In effect, the 175 being run slightly deeper, running a larger diameter prop and only running 50 more RPM makes sense. Raising the 175 SHO ¾” higher could be 100 RPM, running the same 14 ½ diameter Pro Series prop can add at least 100 RPM, forcing you to run a 25” to bring the RPM within 6,000 RPM. This means, setup more like the 150 boat, the Bass Cat should be in the 71 to 72 MPH range, by the numbers. Now were talking 10 MPH faster. I attribute at least 5 or 6 MPH to the gear ratio, and the rest to the power increase. I’ve seen reports of Bass Cat Sabre’s with Etec G1 150 HO (1.86 gears) run 68 MPH. So we can see how gears alone are huge reason for the performance gain.
One thing to note when looking at slip is that the number is based on theoretical pitch, making the slip theoretical. Meaning to say, it’s not an exact number, it’s basically an estimation.
Mercury 150 ProXS
Let’s take a peak at the Mercury 150 ProXS. I wish I could find complete data with one on a Sabre but I couldn’t, so I’ll just get some data together that is close. There is data of the 150 ProXS and 175 ProXS on a matching Nitro Z18s. This is a performance bulletin directly from Mercury but there is one discrepancy we will have to work around. This is the four stroke 3.0L 150 Pro, but in the sheet it says the gear ratio is 1.85? This is most likely a mistake, as it states it’s a 4.88, so we can assume it’s not the old Optimax version. Let’s assume it’s the 2.08:1 ratio that is stock on the new ProXS. Hopefully that’s right.
This test is from March 2018 for both engines and it is a Nitro Z18, 18’ in length, 7’8” beam and has a 1,700 LBS dry weight. I believe Nitro revised this boat in 2019 as the latest model is 2” wider. This Nitro is not very fast compared to the Bass Cat above. Let’s look at some numbers.
The 150 ProXS Nitro Z18 ran a Fury 25” although it didn’t state if it was the 3 or the 4 blade version, in the boattest.com test, they used a 25” 4 blade and numbers were slightly different. Let’s assume it’s the 3 blade. Top speed was 61 MPH at 5925, but if you look at the chart it is 61.5 at 6200 RPM. That’s interesting because the operating range is up to 6000 RPM, most engines can go over slightly before hitting the limiter. Boat Test did 60 MPH at 5770 with 25” 4 blade, so you can see how losing a blade raises RPM when pitch is the same, in most cases.
How does this compare to the Yamaha on the Sabre? Different boat obviously, but similar. The Nitro is slightly heavier, the Merc is spinning a higher pitch prop and has slightly lower 2.08 gears. So, they are pretty close being withing 1 MPH; both are known to be pretty hot 150 HPs, with the Mercury achieving 163 HP at the propshaft. We do have a report of of the same Nitro Z18 with the 175 ProXS, let’s look at that as a comparison.
With the four stroke Mercury 175 ProXS and a 22” Tempest prop the Nitro did 63 MPH at 6011 RPM; the Tempest is a 14 ⅝ diameter. Boat Test used a Fury 23”, assuming it’s a 3 blade, and got 62.5 MPH at 5800 RPM. Those are bad numbers for that engine in comparison to the 150. Let’s see if there anything obvious about the setup difference leading to that. You would assume the big V6 would be much faster than the 4 cylinder.
Details are vague but they say transom height on the 150 Pro is 4”, and 5.5” for the 175 ProXS. Assuming this is ventilation plate above the pad. The 150 25” Fury combo is seeing 9.55% slip. The 175 22” combo is seeing 7% theoretical slip. Something isn’t right about that setup.
You would hope there is much more to be had out of the 175 ProXS, although it’s a very heavy engine, it should be faster than the 150 ProXS. This just proves how critical setup, prop selection and the right engine is. Horsepower is nice but not everything. The 150 had .5” more setback, 17” total than the 175, which would not be much different. Although both are pictured mounted directly on the transom, so the Nito must have serious built in setback.
In this case, you would be hard pressed to argue for getting the bigger 175 ProXS. You might try using a 24” Tempest, even dropping just over 100 RPM, but possibly changing a few things, you could probably get 66 to 67 MPH and then it makes sense. But it’s hard to say not actually driving or actually seeing the setup. Some boats just can’t get the lift required to get going and this Nitro has a really shallow deadrise with a funky design and is a little heavy. The best test would be to run them all on one hull like the Bass Cat Sabre.
Evinrude 150 HO G2
Next, we have the Evinrude G2 vs the Yamaha 150 SHO on the same Ranger Z18. The one with the Yamaha is a Z18C, same hull but has the added side console and is 25 Lbs heavier. Another note, the Yamaha was tested with a passenger, the Evinrude solo. Compared to the Sabre and Nitro it’s right between them in weight, has a shallow 16 degree hull and is equipped with a trolling motor and three batteries, equipment sport boats don’t have to worry about. Let’s dig in.
In the 150 HP category, the 2.7L Evinrude G2 has a huge advantage over the 4 cylinder four stroke competitors, obviously the Evinrude is a two stroke and it is a V6. Although it’s a smaller displacement than the others, the Yamaha is a 2.8L and the Mercury is a 3.0L; The G2 has two more cylinders firing on every stroke. The G2 150 holds no weight advantage, without the integrated steering, it weighs 495 Lbs, about 15 Lbs heavier than the Yamaha; with the Merc being the lightest at 455 Lbs. Evinrude weighs their engines as they ship and the Merc is weighted without its heavy cowling, which the Evinrude doesn’t really have so it is a little closer than the numbers suggest. Let’s see how the big Evinrude 150 does.
With the Evinrude G2 150 HO, the Ranger does 58 MPH, equipped with a Raker HO prop: 14 ½ diameter, 24” pitch. At first glance, that’s not good. These heavy bass boats aren’t all that fast. This bulletin isn’t very detailed, the chart says 5800 RPM and 58.15, putting the prop slip at 4.5%, again a theoretical number just for reference. No jack plate and the only thing it says about setup is the engine is mounted on the #4 hole, which isn’t helpful. One significant difference with the 2.7 G2s is the 2.17 gearing, it’s really low. Let’s see how a competitive 150 does on the same boat.
A Ranger Z18 with a Yamaha 150 SHO is a good comparison. Both the Mercury and Yamaha are really strong 150s. With a Pro Series 21” prop (14 ½ diameter) mounted on the #4 position, same as the Evinrude, we see 55 MPH at 6000 RPM. On the data sheet, the engine is a 150 SHO (Yamaha VF150LA) but it says 2.7 but hopefully that is just a mistake on Rangers part, mistaking it for a F150. Not a great number but let’s see compared to the Evinrude. With a 2:1 gear ratio, running a 21” prop, you wonder if a 22” raised up one hole, or utilizing a jack plate could push it up to 57 or 58? Most likely. The Evinrude is actually setback 6” because of its unique swivel bracket, so it stands to reason that is a slight advantage.
Interestingly, the time to plane on the Yamaha is better, 3.58 seconds over 3.9 for the Evinrude. This is in large part to the lower gears on the Evinrude. The argument for lower gears is more torque but in the real world a lower pitch prop is going to help get out of the hole more than gears, in most cases. If you could run a 22” with almost no tweaking to get the top speed close, and the cruise speed really close, it would be hard to say which one is better on this boat. Keep in mind the Yamaha boat had one extra person in it and heavier test weight of 2864 Lbs.
Technically, that 24” prop provides a slightly faster cruise but the Yamaha gets better mileage at 3,000 RPM and 3.7 GPH at 24 MPH, compared to the G2 at 3000 RPM at 4.71 and 27 MPH. A smarter person than I can calculate range by the extra 3 MPH, but I’m not too worried about it.
Since Ranger didn’t make this boat when the Mercury ProXS came out, I had to use a Ranger Z518, which replaced it and is only 2” longer and 1” wider. With a 23” Tempest it ran 55.5 at 6000 RPM. The test was from Boating and was very vague, with the speed based off their chart, no report of setback and height but it did have two people on board. This puts it inline with the Yamaha.
What is the final word based on the tests above? The truth is, this is a very competitive category with 150 HP being one of biggest selling HP ranges in outboards. All of these 150s are capable engines. Here is how I rank them and a few of the criteria. I want to use value, performance and features heavily but I want to consider details like gear ratio as well, as it affects performance greatly.
To me, the Mercury 150 ProXS is the top choice and it comes down to value and performance. It’s the lightest 150 here, not the lightest on the market, but the lightest among these three and is priced very well. Both the regular Mercury 150 and 150 ProXS were designed to be low maintenance cost effective 150s and it shows. The ProXS has low water pickups and a reasonable but not ideal gear ratio. A 1.85 would make this almost perfect for a 150 outboard.
Number 2 is the Yamaha Vmax SHO 150. More expensive but featuring a DOHC design, but a little more maintenance involved make this a great choice overall. No low water pickups hurt it but a decent 2:1 gear ratio make this a solid performer.
Third, but not necessarily least is the G2 150 HO. If this had the 1.86 gear ratio that the bigger G2s have, it would most likely be a better all around performer than the others, moving it up the list. The extra weight works against it a little bit, but the integrated steering is sweet, and when you weigh fully rigged engines, the weight isn’t as big a difference.
For a real test, we need to take the same hull, something reasonably fast like the Bass Cat or better and do all three at once, setup properly. My money might be on the Yamaha in strictly top speed based on the gear ratio but you could mount that ProXS a little higher, so it would be close. On a slow heavy boat, the G2 would probably reign supreme, where the gear ratio and a low pitch prop become an advantage. I’m not sure the G2 would be as fast on a performance boat with that 2.17 gear ratio, it probably couldn't swing the higher pitch fast enough. A real world test would be great.