1 photo
Mercury 115 HP OptiMax

Mercury 115 HP OptiMax

4.0 from 2 reviews

See the Best Outboard Motors in 2019 as rated by Australians on ProductReview.com.au.

Unbeatable Fuel Economy

I have a 2006 Optimax 115 with almost 800 hours on it. The honeymoon period is long over. It has been a good engine, but not great.
It sits on my 19' Sea Boss. It has pulled water skiers, wake boarders, tubers, etc. It has hauled 6 people to and from from sandbars, snorkeling spots and remote islands all over the middle and lower Florida Keys for 11 years. It has worked hard and it is still alive and kicking.
Comparison time: My prior boat was an 18' Wellcraft with a 115 Yamaha. The Mercury is a 3 cylinder. The Yamaha was a 4. The Optimax consistently delivers incredible fuel efficiency, but it definitely does not have the torque the Yamaha had. I attribute that to the extra cylinder. Still, watching my speed the Mercury will get me between 6 to 7 NMPG cruising at 19 knots with a light load. You can't beat that. The Yamaha got me around 4 at best. The Optimax is also the cleanest burning 2 stroke I have ever seen.
The starter died and was replaced under warranty. The oil tank censor died a week after the warranty expired. Mercury did not return my calls on the latter. So much for customer service. The Yamaha never broke down on me...never. I am fortunate that a long-time friend of mine is an excellent outboard mechanic.
The 115 Optimax has been a good - but not great - engine. It came with the boat as part of a Boat Show package deal. I'd buy an Optimax again if it came as part of some great deal.

Date PurchasedJun 2006

Great motor - but beware the hidden costs

Mercury 115 Optimax purchased Dec 2011, now has 120 hrs after a little over 2 years of operation. Pushes a Cruise Craft Outsider 510, GRP boat with ease. Good acceleration. Sounds a treat out of the water. Also one of the lightest motors in its power class.
Great motor, runs beautifully and reasonable fuel consumption 1.1 nm/liter or on average 14 l/hr for an average days outing with some long distance travel.
Motor looks very good after 2 years of salt water service - except for steel swivel pin bush, which is corroded ( silly idea in my opinion)
Unfortunately - annual service costs $500
2T Oil usage high - one specific test revealed 47:1 fuel oil ratio, for an average run with majority of revs sitting at just over 4300. 2T oil is expensive for this baby so you can add $250/year for 2 T oil. Apparently there is nothing wrong with the motor so this oil consumption must be acceptable to Mercury.
I would strongly recommend if you purchase a new motor, do your own life cycle costing. You may find the other motor manufacturers capital costs higher but operating costs a lot lower.
Reliable responsive, fuel efficient, good power to weight ratio and good price.
High 2T oil consumption and high operating costs

Questions & Answers

Sorry, there are no questions yet.


Mercury 115 HP OptiMax
CategoryOutboard Motors
Release dateFeb 2011
Visit official website

ProductReview.com.au has affiliate partnerships. These do not influence our content moderation policies in any way, though ProductReview.com.au may earn commissions for products/services purchased via affiliate links.