R27 OB performance

[Chimo]

After the boat show in Sidney I am having a mild case of 2 Ft virus. That would take me to an R27 OB if I wanted new or an R29 used. The new R29 is out of $$$ range.

Thinking of performance, I am most interested in continuing to cruise in the 15 mph range. The only tested figures I came across for an R27 OB were from Boating World "At 4000 rpm, the R-27 noodled along at 18 mph and the F300 got 1.5 mpg, according to the Yamaha gauges." Sure, I can open up and get 40 mph but I more of a 'journey' than a 'destination' person these days. I want more than hull speed but not 20+. Has anyone done any curves in 100 rpm intervals for an R27 OB?

 

[Maggie Anne]

The performance data can be found here.

https://rangertugs.blob.core.windows.ne ... -sheet.pdf

The sweet spot is a bit faster than you said you'd like.

 

[Chimo]

Thanks, 1.77 mpg is not too bad

 

[Red-27]

in my experience the slowest I plane at is 16mph ish and got about 1.2 mpg at that speed. my best cruising mpg was about 1.3-1.4mpg at 30mph about 4900-5000 rpm and at 20mph it was closer to 1.2-1.3 mpg. i can usualy go about 12mph max without plaining but slow no wake is usualy around 5-6mph at 1000rpm and around 4mpg.

I do have the dinghy lift on the boat and am sure i added some weight with cruising supplies like food, clothes, tools, and anything else you usually bring on boat trips. I generally have water in the tank and fill my gastank before i go out. I also have the luxury edition with the AC unit and battery bank.

This season i have installed auto trim tabs which seems to be a noticeable mpg increase of .2-.3 mpg but i havent had any long term date to look at to see the full effect.

I hope this helps as i think their data sheet is not really realistic as i have never seen anything close to 2.0mpg. also you may like to move slower but a faster boat mean access to further cruising grounds in a timely manner where you can slow down to your hearts content. also if you ever find yourself crossing a great lake you dont have any scenery for several hours anyway and you can turn a 8-10hr trip into a 4 hour trip

 

[S. Todd]

We had a R25SC and traded up to a R29S with the 320 hp Volvo. We cruise the Great Lakes and when the wind blows going fast is not a very comfortable option so there is lots of 12 mph travel. My analysis was that the R29 inboard actually did better in the fuel economy department at 12 to14 MPH and based on what the other posters have said it looks like if you are comfortable traveling at 20 mph or less there is no appreciable difference in the fuel economy between the R27 OB and R29 IB. My typical cruise at 14 to 16 MPH gets me about 1.3 MPG with the R29, about 1 MPG less than what we got in our R25SC.

 

[Submariner]

One thing to consider when looking at the factory performance sheet is it's an empty boat with partially filled tanks and 3 guys from Yamaha on the boat testing in calm conditions.

We load our boat as our second home, plates, silverware, spares, tools, clothes, food, liquor, and other baggage onboard. Then we leave the dock with all our tanks full except for the SAN tank.

I upgraded to 4 blade PowerTech prop instead of the 3 blade factory/Yamaha prop. The 4 blade is better stern lift, improved hole shot, more control in bad seas and while docking (especially when in reverse), but at the expense of a little less fuel efficiency when cruising at 25 knots on plane. And the 4 blade drops WOT speed about 2 knots. The 4 blade also lets me stay on plane down to around 13 knots so I can comfortably travel with my friends who have an RT29 or RT31. I cruise usually between 25 and 30 knots.

The best illustration is this... Some friends of ours took delivery of a brand new RT27-OB, factory stock, with the dinghy lift. My boat has no dinghy lift, but has the 4 blade prop. We both filled up our gas tanks at Everett and cruised together to Roche Harbor and back to Everett. They burned 100 gallons of fuel for 1.53mpg, while I burned 111 gallons for 1.38mpg. There's a lot of current to run through between Everett and Roche Harbor as it's 65nm each way. And I experience current in different directions through our journey around the San Juan Islands. All it takes is a 2 knot head current to reduce fuel efficiency by about 8%. Or, travel with 2 knots of current to gain 8%.

The Yamaha display rounds up or down the MPG reading. It'll show 1.2, 1.4, 1.6 mpg... I've never seen it show 1.3mpg, for example. In my testing I recorded speed and GPH and had a spreadsheet do the mpg calculations.

Here's some real world stats of testing I have done.
https://www.letsgochannelsurfing.co...kxcs0cum-aa3076ef-2a33-441b-860a-294d5859acd1

 

[CruisingElvinRay]

For comparison, my R-23 would not be happy cruising below 20mph. She would be plowing a huge wake and getting terrible mpg. Her best cruise is at about 24-26 mph, 4600 rpm, getting from 2.1 to as high as 2.6 mpg depending on conditions.


Sent from my iPhone using Tapatalk

 

[Maggie Anne]

In normal outings around the San Juans, with a clean bottom, 4300 RPM will get me 28 mph and about 1.9 MPG. On last summers trip to Alaska, I was much heavier, and it took 4800 rpm to get to 28 mph (which is roughly what we typically ran at on that trip) and I averaged 1.6 MPG over 2600 miles. It does make a big difference what you set your engine trim at. I've found about 4-5 bars on the yamaha trim setting gives me the best mpg, if I trim the engine fully down I lose rpm's and drop about 0.2 MPG

 

[BB marine]

After the boat show in Sidney I am having a mild case of 2 Ft virus. That would take me to an R27 OB if I wanted new or an R29 used. The new R29 is out of $$$ range.

Thinking of performance, I am most interested in continuing to cruise in the 15 mph range. The only tested figures I came across for an R27 OB were from Boating World "At 4000 rpm, the R-27 noodled along at 18 mph and the F300 got 1.5 mpg, according to the Yamaha gauges." Sure, I can open up and get 40 mph but I more of a 'journey' than a 'destination' person these days. I want more than hull speed but not 20+. Has anyone done any curves in 100 rpm intervals for an R27 OB?

When we were cruising in Florida 2 years ago we met up with a couple that had a 27 Ranger outboard. We planned on cruising to the keys together from Goodland Florida to Marathon Key. I told the Tug owner I planned to cruise 14 KTS Average (16mph) He responded with "Ok I will try to cruise with you but I don't think I can run the boat at that speed without a lot of throttle up and down" We left a few minute earlier knowing that they could catch up. When they caught up he said there is no way I can run at this speed. He stated, to keep the boat on plane comfortably he needed to be cruising in the mid 20 MPH range. This day of cruising, the water was kicking 1.5 to 2 foot chop. After about 1hour of the Tug leaving us he radioed back to me and asked where are you at. He was cruising 25 mph and I was at 16mph. I gave my location. He said he was getting beat up and was planning on going into an anchorage ( Shark River). He asked how we were doing. We were very comfortable cruising at 16 MPH with a smooth ride just a lot of spray coming over the bow. We met them at Shark River and had a nice evening with alcoholic beverages included. The conversation was " I wish I could cruise at 16 mph like you can. My comment was I wish I could cruise at 30 mph like you can.

My point if you want to cruise and enjoy 12 to 15 kts. Don't buy a planning hull Outboard. If you want to cruise at 22Kts + don't buy a semi planing hull ( semi displacement hull) There is no right or wrong as long as you know how you want to cruise. Chimo if you are interested in cruising at 15 mph I would not think about the outboard model Tug. There are plenty of well built boats out there that will fit your 2 ft Virus and give you the ability to cruise comfortably at the speed you want to cruise and give decent fuel economy. I have a 34' Mainship Pilot that gets the same fuel economy as my C26 did at 14kts. It is using 2 diesels instead of one and burns 9 GPH average same as the C26. It weighs 16000 lbs dry weight Cutwater C26 6700lbs. If I want to cruise faster I can with a top speed of 24Kts the Cutwater was 20kts on its best day. Yes I do use a lot more fuel running WOT GPH but MPG compared to the Cutwater is the difference of .4 gph wot but I'm going 4 kts. faster. There are a lot of nice boat in the sea. The Rangers and Cutwaters are among them. Keep an open mind when the 2' Virus kicks in.

 

[Submariner]

Putting on the 4 blade Power Tech prop with the Lenco Autoglide, that automatically controls the trim tabs, was a game changer for me.

This combination allows me to effortless cruise at 10 knots or less for slowboating. Or I can pop up on plane and cruise from 13 knots up to about 33 knots. The fuel efficiency doesn't really change much for me when on plane. I find the sea conditions affect me mostly. Like, when I see 1.2mpg on the Yamaha display, and adjusting the engine trim just does nothing to improve... then I look at the direction of the current and find I'm going against it. Other times, I'll see 1.6mpg and just know that I'm going with the current at that point.

There are sea conditions in which it just gets too bumpy cruising on plane at which point, I drop off plane and set my speed around 7 or 8 knots and slowboat for a bit to get through that section of water.

Sometime this summer I'm going to go find me some flat flat water at slack and update my spreadsheet for RPM, GPH and Speed charts. Maybe I'll head over to Lake Washington and run the tests there.

 

[Chimo]

My sincere thanks to everyone who responded. Very much appreciated! I confess that the answers were very much what I expected based on hull design. Your responses provided excellent vaccination against the 2 ft virus. The 27 would not cruise as we wanted and also has the deal breaker of having the head in the forward berth. The 29 is simply too much of an investment for the time we spend cruising in the tug. Other things to see and far flung countries to visit.

Thanks again