The Mercury 300 V8 is the answer to the question of why a 300 hp outboard would be a V8. The 4.6L V8 four-stroke produces 300 hp at 5600 rpm and weighs 527 dry pounds, which is 35 pounds lighter than the Yamaha F300 V6. Idle is meaningfully quieter than any V6 in the segment, the Mercury Active Trim is the most refined automatic trim in production, and the SmartCraft system pipes more engine data to a Mercury VesselView display than any competing brand does to its native screen. The trade is on dealer-network density east of the Mississippi, where Mercury parity has improved over the last four years but Yamaha still has more coastal dealers per mile of saltwater shoreline. We ran a pair of 300 V8s on a 28-foot bay boat for the 2024 season, no surprises, and the Active Trim setup paid for itself in fuel economy at cruise.
For the full scoreboard, what works versus what does not, year-and-trim guidance, and pricing as of April 2026, see our roundup Best Outboard Motors in 2026.
What works
- 527 dry pounds is 35 pounds under the Yamaha F300, real transom-rating headroom
- V8 idle is quieter than any V6 in the 300 hp segment
- Active Trim is the segment's reference automatic trim system
- SmartCraft data layer pipes deeper engine info to chartplotters than any rival
- MSRP undercuts Yamaha F300 by $800–1,200 on equivalent rigging
What does not
- Dealer-network density east of the Mississippi is improving but still trails Yamaha
- Closed-deck aluminum with iron liners is a different long-term wear pattern than Yamaha's plasma-bore
- Resale at five years runs 5–8 percent weaker than Yamaha F300
Pricing, April 2026
- New: $31,200–34,600 new (2026 MSRP, rigged)
- Used: $19,800–27,500 (2020–2024 powerheads)
Long-form review
The full Mercury 300 V8 long-form review republishes in July 2026 with on-the-water testing notes, a 6-dimension scorecard, fuel-burn or charge-time numbers, and the trim and year we would buy. Until then, the roundup link above is the decision-grade read.