The Best 300 HP Outboard: No Contest

When you are looking at a new 300 HP outboard with a 20” midsection you only have two manufacturers to choose from; Mercury Marine and Suzuki. When we look closely at the features and options in the 300 range, it is apparent this is one of the reasons Mercury Marine has continued to be incredibly successful in the outboard game. Mercury, similar to many auto companies, has leveraged platforms to deliver choices to consumers across a broad product range. Let’s look at the 300 HP engines on the market and why Mercury Marine dominates.  

Mercury makes several variations of a 300 HP based on the 4.6L V8, so the consumer can get an engine for their specific needs, including a Verado, ProXS, Racing version, the regular Four Stroke and Sea Pro model. Each has variations suitable for different applications. Suzuki makes two different 300s, one 20” and they make the larger 4.4L DF300B, with the contra rotating gearcase in a 25” and 30”. Yamaha does make a nice 300, built on their venerable 4.2 V6 platform but not in a 20”. Why Yamaha doesn't’ make a 20” 300 is beyond me. Yamaha has a very successful SHO line based on the 4.2, mostly geared toward performance fishing and could easily accommodate a 300 HP.

Mercury Marine

The 4.6 V8 covers a lot of ground, 200 to 300 HP. It’s a great engine overall, especially as a 300 ProXS model.

The best 300 HP on the market for anything performance related is the 300R from Mercury Racing; by a long shot. The second is the 300 ProXS, for those that need a Torque Master gearcase and don’t the need the extras the R offers but are still capable of running up to around 85 MPH. What makes the 300R so incredible is the fact that it has just the right options for almost any user. There are different mid sections, the regular tri-ram with solid lower mounts and the HD midsection for more serious offshore use, with a forged bracket, single ram trim and external trim pump. With the HD, you can get a Mercury Racing wing plate for tie bars or a side mounted steering ram as well. 

Incredible power and an array of options make the Mercury Racing 300R a killer for performance outboards. Seen here on a Tuff 24.

One of the biggest differentiators in outboards is the gearcase and this is where Mercury kills the competition in every model. The 300R, specifically, has 3 available gearcases, the Sport Master with two gear ratio options (1.75:1, and 1.60:1), the Torque Master and even the massive 5.44” for big heavy boats running the gearcase deeper in the water. Consider that the 300R is available in L-20”, Xl-25” and XXL-30” and truly you can spec a 300R for almost any boat with any configuration. 

The 300R has a competitive starting price, although the HD versions can get up there, you simply have no other options on the market that combine these features. Furthermore, the tuning Mercury Racing has done to the 4.6L V8, like performance cam shafts and a performance intake manifold, means it can rev up to 6,400 RPM and makes far more power than other 300 outboards. 

Mercury’s ProXS line is geared toward the bass and performance fishing market in general and are great repower engines. Priced right, with a little performance touch; RPM increase, upgraded gearcases and are a little lighter than the non Pro engines due to a lighter cowl. For the 300 ProXS, the formula is the same, 6,200 RPM, Torque Master and it is the lightest 300 on the market. If you’re boat runs under 85 MPH, this is the best bang for your buck. The regular Four Stroke 300 is available with the 5.44” case and a variety of colors and is great for big heavy boats, as is the Verado with “AMS” (advance midsection) and integrated steering.

Suzuki Marine

This is where Suzuki comes in. Although Suzuki doesn’t make anything performance oriented, the gearcase design is quite good, featuring water pickups on the front of the bullet shaped lower unit. You only have one gear ration available, a 2.08:1 and it weighs 570 Lbs. which isn’t too bad because there is a discrepancy in how manufacturers weigh their outboards, making for some inaccurate claims. In the 300 HP range, 520 Lbs. to 570 is about normal. The now defunct Evinrude G2 was the lightest 20” 300 at 545 Lbs which included the cowling and steering system. 

With Suzuki you get a 4.0L DOHC V6 priced extremely well. This is a repower engine for heavy boats, geared for low end torque and not for performance but that’s a large part of the market. Repowering a center console or old sport boat that isn’t getting past 60 or 70 MPH would make it attractive. Available in white and black, the modern looking V6 from Suzuki is a winner for their strategy. Worth noting is that Suzuki was first to market with a V6 four stroke 300 HP outboard.  

Interestingly, Suzuki has recently added this gearcase with taller 2:1 gears in their 4 cylinder SS series 150 and 200 HP outboards. This is new and welcome departure for them as they really stuck with the extremely low gear strategy, making the latest 4 cylinder Suzuki SS engines very competitive now. I don’t foresee Suzuki Marine making a performance V6 necessarily, but they seem receptive to trying new things lately. An SS 250 / 300 HP V6 with taller gears and stiffer mounts would be interesting. The current 250 SS is just a decal motor essentially. The team at Suzuki is dedicate and are true “boaters” so you know they will be constantly innovating. 

I fail to see what Honda Marine’s strategy is overall. In the U.S, they just don’t compete but I do believe they have strong global sales. I have met a couple of the guys at Honda Marine and they are really nice guys and I would love to be excited about new products from them but they don’t seem interested in competing with Mercury, Yamaha or Suzuki; all of which have more selection in every HP category. Honda doesn’t even make a 300 HP outboard. 

With an incredible array of products based on the same platform, Mercury has leveraged themselves into every market category in not only the 300 HP range but almost every HP range. Options, consumers need them and love them but they need to be coherent and targeted. Mercury has executed this idea very well. Suzuki continues to fight for market share and is really strong against Yamaha. In the 300 HP horsepower category, it is simply no contest, Mercury Marine dominates.