Boat Towing Fuel Mileage?

So the last time I checked the mpg on my truck, it got roughly 18mpg hwy miles. I have never checked it while pulling my boat because I have yet to pull my boat really anywhere very far. I was just gonna see how you guys thought pulling my boat might effect my fuel mileage? I drive a 00' GMC Seirra, ext cab, 4wd, 5.3 v8. My boat is a 03' G3 HP170 w/90 horse yamaha. The "package weight"(boat, motor, trailer) on my boat according to G3 is roughly 2000lbs. Just curious as to what you guys might guess my MPG would be while pulling my boat on the highway? I know a few of you guys have boats similar to give me a rough idea. :-k

I have an '03 Silverado 2WD with same cab and motor and that's about what I get hwy mileage too. If you want to wait until October when I pull my boat (Tracker ProTeam 190 w/90 Merc which weighs in close to the same as yours) down to Dale Hollow, I'll let you know what I get. I did use the truck to haul a fully loaded enclosed trailer with a flat front to Texas and was thankful to get 12 MPG. Weight was prolly close to 2000 but wind resistance with the flat front on the trailer was like a parachute. Trailer was 6'x10' and 6'6" tall. Around here I use my Trailblazer to haul my boat and my mileage drops from 19MPG to about 15MPG

So I can probably figure anywhere between 13-15mpg. My truck does have the lower geared rear-end(4.10), so it doesn't get that great of fuel mileage anyway....so I don't think I would expect that much of a drop. Plus that 18mpg was figured from last march when I drove to Reelfoot lake, since then i've added an aftermarket muffler too(Magnaflow...which is supposed to be one of the better ones to help with mpg).

On a new 5.9 cummins in my HD2500, 1800 mile round trip, 65 MPH pulling 6000+ I was getting 11 to 12 MPG , she will get 23 mpg empty.
3.73 rear end with a 6 speed man.

https://s248.photobucket.com/albums/gg179/welderalbum/?action=view&current=P6290416.jpg

i have a smart engine on my 09 sierra, (375 horsepower but you can push a button to shut it down to 6 cy or 4 cylander when not needed ) i was getting 26 mpg at 65mph. Now if im driving like 45-50mph i can put it in 6cyl at 35mpg

My tundra gets 21 highway ad 17 while towing . I was only getting 17highway and 13 towing until I switched to purple royal synthetic oil It made a huge difference

I have a 2000 Chevy Ext cab w/5.3L and get 16mpg mixed regular driving and towing my boat.

Hey guys , to say you get 21/22 hwy and 17/18 towing , thats cool but WHAT are ya pulling ?

I drag 6000 +Lbs , 9' wide on the trailer and 11' tall , 115 Gallons of fuel, 225 HP honda [ see above link to the picture of truck and boat ]

Now if I was draging a 14' skiff that was no higher than the bed of my truck , I would still get 23 + MPG.

We have guys over on aluminumalloyboats.com that drag 15,000 Lbs of alloy down the road :shock: y'all should see that , WOW.

There is another forum just for alloy thats been around for YEARS , probaly the 1st [www. boatingsportsman.com ] and they trailer all over in Mtn. country and there boats aren't light either. They run alot of Big Block's and Diesels in their boats

I am towing a Triton 21x with a 225 hpdi not the lightest rig out there...

RedBug , how many miles were on your truck before you switched to the Royal ?

I changed it last summer when my truck had 21k on it my truck is an 05 and now has 29k I towed the boat down to kerr lake in NC this past fall and got 17.5 mph on that trip I am planning on using it in my trans and rear when i change them this spring.
I also run purple royal in my lower unit on my yammy...

Red , thanks for the Info. There are some guys here in Texas running it that I know and so far they seem to be happy with it.

How much do you pay for that Purple Royal? What kind of interval between oil/filter changes? What filter? I use Amsoil oil and filters and they had a major price increase that has me looking elsewhere. May 2008 I paid $88.80 for a 4 gallon case. In December it jumped to $103.40. Currently I change my filter every 6 months and the oil every 12 months. I might start buying from a local store and save on S/H costs as well.

My tundra takes 6 quarts of oil I change t every 7500 miles They say it can go longer but i am okay with the time frame I paid $45.00 at pep boys to have it changed I can't be bothered crawling under car and trucks anymore.


Wayne

we have too many mountains here to get accurate gas milage

I have a 06 Tundra and I'm running real close to redbug. Pulling my 14' Alweld at 65, I get around 18MPG and @ 72MPH about 17MPG. Pulling the 24' Fishmaster w/225 Merc at 65, 14MPG. Pulling a 26' Robalo WA forget about it, don't want to know.

My Alweld with a 4-stroke gets better MPG than my truck (even empty)!!