Real world mpg , 300 xs vs 300 x above 4000 rpm

[Skater 32]

We all know how the Optimax performs in the MPG dept due to the direct injection and fisherman who run low RPM all day are the biggest benefactors but does anyone have Data ( not theory) comparing 300 Opti to 300 x starting at 4000 RPM and above . I always heard 35% better MPG down low but never really new @ higher RPM ( 4000 +

Larry

[TUNNEL T]

SKATER 32 , i have a f-26 with xs's and two buddies with same boat and x's ,yes they would tell you about 40% better mileage and yes thats wound up .they are a little fasterthough .hope this helps you TUNNEL T

[offshoresteve]

My SC5000 screen shows 30gph going 90mph im my 28 Skater....3mpg

[Frank Molé]

my sc5000 screen shows 30gph going 90mph im my 28 skater....3mpg

whats up steve,love that skater...:thumbsup::cheers:

[FullAuto9]

Skater32, There was a thread on oso about a new 32 Spectre that had the gph numbers for twin 300xs. Hope this helps.

[time warp]

My SC5000 screen shows 30gph going 90mph im my 28 Skater....3mpg
That's for one motor correct, so it's really 60 GPH so 1.5mpg? Or does the SC5000 show combined flow? Hard to believe 15gph per motor.

[Maritime_Eng]

That's for one motor correct, so it's really 60 GPH so 1.5mpg? Or does the SC5000 show combined flow? Hard to believe 15gph per motor.

That should be for both. With my 30 Motion with twin 250xs's I can run 80mph and average 3mpg. These new engines are very effiecent.

[SCT]

Do you guys know of anyone that replaced a 300X(s) with a 300XS(s) on the same hull? What was the mph difference?
Thx-

[Maritime_Eng]

Do you guys know of anyone that replaced a 300X(s) with a 300XS(s) on the same hull? What was the mph difference?
Thx-

I replaced 2.5 (280's) and went to 250xs's. My best speed with the 280's was 107mph, with the 250xs's the best I have seen is 98mph. I think 100 is possible with the 250xs's. The 300xs's would run about 104mph on my hull.

[Toffen]

Hi!

I had a Promax 300 for 7 years. The engine consumed approx. 55 litre per hour at 4,000 rpms running 50 mph. 55 litre is equivalent to 14,5 gallon per hour. I now have 2 x Merc 2.5 EFI (280 hp each) with PCU's. The consumtion is approx. 80 litre per hour at 4,000 rpms and 50 mph. Thats equivalent to 21 gallon per hour.

Good luck!

Cheeers, Toffen

[powerabout]

that 30gph for 300hp sounds a bit high
Thats the rule of thumb for old carby engines i.e. 20gph for 200hp worst case

[NAVISPEED1]

Hi Skater 32, this guy mentioned that he had a 7 MPH loss :eek: when he swaped from 300x to 300xs.

http://forums.screamandfly.com/showthread.php?215184-Official-22-velocity-speed-and-set-up-thread.

[Skater 32]

Thanks ! I decided to have a pair of 3 litre EFI Strokers built from Shaun Torrente , 350-370 hp each . My 32 Skater should run 105 -110 MPH

[NAVISPEED1]

:thumbsup: Cool!! Good luck Buddy!!

[Skater 32]

Thank you !! They should run there ass off . Only a few 3 litre EFI engines have been built with 300 XS 3.2 stroker crank

[NAVISPEED1]

Uhhffff, sounds Killer!!!! :thumbsup: Keep us post it!!!
:cheers:

[bigtis]

I've always run 2.5 200's and 225's. I've now got a 2.5 200xs, and below 4K the fuel comsumtion is cut down by close to half the amout of fuel. above 5500, I think she's burning the same amount.

[bigboy]

Bigtis is that half the amount compared with the 2.5 200 or the 225?

I wonder if yous aw any difference in speed from going to the 200 to the 200xs's? How cdo you compare both engines? I have a 2.5 200 carb now.

Thx

[jpf091959]

Sorry don't want to hi-jack your post, but I am very impressed with the fuel mileage of the 300xs'

I have Happy Pigs old 25' Motion. He was running 300X's, I think he was running 111 in fresh water and ~114 in salt.

I bought it with 225's and ran 90 mph.
I have just replaced the 225's with new 300xs' with offshore mids and sportmaster 1.62's. It came out of breakin mode last week. I have hit 106 into about 8 mph wind off the front right, on the Columbia River. I had the benefit of a few mile an hour current. The engines have to be getting at least 3 mpg, just not using much fuel.

I want more speed any idea's would be appreciated. I mounted the engines directly to the transom, 1 -1/2" above, gearcases straight forward, no toe, props turning out. I run stock mercury 3-blade 15x34's. I think the engines are turning 6000 rpm, I haven't looked at the tach's close enough.

I have less than 4 hours on the engines, so they may loosen up some more.

[crxski]

I don't get how the outboards are loosing speed with direct injection.... Ski-doo just came out with there Etec on the 800r motor and its gained a few hp and revs faster, no smoke gets 19mpg and has more torque...

I've read 5 articles on Etec and its amazing, modding might be a pain but its efficient all the way up till 90% throttle, WOT only alittle better, pending (sled only) exhaust valves.

[NAVISPEED1]

:cheers:Hey Skater 32, Any progress with the 300x mods??

[Skater 32]

we are process of laying graphics out .Here is rough idea, color is benz silver and new camaro synergy green . The stripes are going to be snake-skin appearing

[NAVISPEED1]

Nice, it will be a sweet looking cat!! :thumbsup:
And how about the motors?
:cheers:

[Skater 32]

engines are just about done but spoke to Shaun and said have them ready end of this winter . I have had this project for two years now and getting restless and to be honest I want a 40 Skater with big power and # 6 drives so I may not have this long

[NAVISPEED1]

Cool!! Just keep us post it on the progress!!! 32's are really cool, I'll be pushing to at least get a 24 in the next couple of years, I'm thinking in getting a hull and then work on it. We'll see. Take care!! :cheers:

[Skater 32]

Trust me **** is for free , just saw a 32 with 800 SC and # 5 drives go for 28 k on trailer . 24 is too small and in my opinion a death trap

[NAVISPEED1]

Hmm, interesting!! :confused:
Well, my idea is to go with the economic set up package, a 24' either Skater, Predator, Liberator or Motion and ad a single 300x Simonized to 350hp+ I know it won't be the fastest 24 out there but 95mph+ will be fast enough to have some fun without braking the bank. insurance wont hurt much either. We'll see!!
Take care Buddy! :thumbsup:
:cheers:

[WSJR1]

This is kind of where I am. We may be upgrading to a larger boat from a Hydrostream Vector. I'm trying to find the perfect boat for what I'd like to do.

I'm thinking open bow for more folks, like a dcb open bow, or a ultra custom shadow deck 23. My wife really wants the room.

We have a few smaller rivers near by then we have some bigger waters and even the mouth near the bay in Virginia. Bay's probably a little rouch, normally for what I'd like.

But, I'd like to stay with a large outboard, 300 I guess and just go as fast as I can when I want but normally just run around cruising mostly, tubes etc.

Now looking at mpg fuel rates and boats.


Hmm, interesting!! :confused:
Well, my idea is to go with the economic set up package, a 24' either Skater, Predator, Liberator or Motion and ad a single 300x Simonized to 350hp+ I know it won't be the fastest 24 out there but 95mph+ will be fast enough to have some fun without braking the bank. insurance wont hurt much either. We'll see!!
Take care Buddy! :thumbsup:
:cheers: