All kinda new to me:) 02' F250 PS7.3L

[Ed-in-Maine]

HI All,
Just discovered this site and all I can say is "WOW" Thumbs up to all of you and your incredible MPGs. I've always loved cars that had high performance and low fuel consumption. My classic example was back in the early 80's comparing the 911 to the Corvette. I went for the 911! Race car when I wanted and still hit 30+ cruising down I-95 to Florida!

But my current ride, 02' F250 crewcab long bed (22ft stem to stern) 4x4 7.3l diesel isn't in anyway a sports car but it is an incredible towing machine. I routinely get 16 when towing my 26ft MacGregor sailboat, about 2200lb total trailer weight and the truck bed loaded. 16 is on I-95 south of WDC, north through PA, NY and up to Maine I get about 15. Not towing about 17-19. Oh and I never exceed 65mph, the momentum of this rig just scares the hell out of me should anything go wrong

Question: I have a tall ARE cap, which is nice but not absolutely needed. I'm sure there is a huge suction back there since the rear of the truck looks like a 7ft high, 6 ft wide vertical wall.
Any thoughts on switching to a simple bed cover? Up to this point I've kinda thought the cap gets the air over the front of the boat and helps the mpg while towing.

The bow of the boat is about 2 ft higher then the tailgate. I wouldn't mind optimizing the aero for towing since better than 50% of the time it is towing.
Thanks
Ed

[larrybuck]

Welcome! That's not too bad of a towing mileage figure.

There have been several posts on cleaning up full sized PU's

Dig beyond the 1st page of the Aerodynamic section, and I'm sure you'll find
gold nuggets in there!

[Frank Lee]

Can't imagine a two foot F250 towing much of anything? ;P

If the boat is above the tailgate I'd say it's a safe bet the topper helps more than hurts, and also helps more than a tonneau. But then the question is, is that boat back there all the time or just once in a while? Then the tonneau MIGHT be better than the cap, but that may be a YMMV thing.

[Ed-in-Maine]

Larrybuck- Yes I have been digging but I haven't seen my situation, although somewhere I saw a kind of pop-up aerocap that might work nice.

FrankLee- haha maybe at two feet it would handle more like a sports car than a bus I am thinking the same thing about the cap. I'm towing a good 40-50% of the time.

[slowmover]

Big Dave is your new friend.

The tall cap would come off of my truck. Mine is cab-height and follows body contours but a 3/4's or full headwind makes it a problem. In a tailwind, though, it may actually help a bit.

A hard tonneau would be better, but an AEROLID would be best.

.

[skyking]

It is pretty tough to project a good effect from the truck with conventional trailers, and much worse with something like a sailboat.
The distance between the two rigs makes them behave largely like two separate rigs.
If you only lose 3 MPG towing I'd say it is not a good pursuit in my opinion. Better to reduce the truck as slowmover says, and see what that nets you. I would go with a full aeroshell.
Nice toy by the way, I love sailing.

[Ed-in-Maine]

Hi skyking,
I just checked out your diesel truck mpg. How are you driving that you get up to 26mpg? Or is your truck just that much more efficient than my F250? I drive pretty conservatively e.g. rarely exceed 62 mph(GPS not speedo), and my best cruise down I-95 in pretty flat country is 19mpg.

skyking, slowmover An aerolid would be sweet but it's not in the near term. If I had time to do one thing would a deep air dam or a duck tail have better FE effects? Or something else?
Thanks
Ed

[slowmover]

How are you driving that you get up to 26mpg? Or is your truck just that much more efficient than my F250?

Some of us have genuine diesels, the rest wish they had a Cummins. (Click on the Fuel Log link below my signature). And we have another member who walks on water . . little boys like Skyking and me are barely able to stay within 70% of what he & his Cummins can do.

Ed-in-Maine, kidding aside, I recommend you do a search of all threads started by Big Dave as his 7.3L Ferd is a great template of ideas for your truck. I'd PM him after a thorough read of those threads, and then of his other posts here (he also posts extensively on Ford forums). For dollars and cents experience, he's your man (to get things started). Until quite recently no one else had numbers even close to his.

The real money is in driver training. Costs nothing & pays the biggest returns. Plus, no matter age or vehicle there is always more to learn: I hit a nice marker this past week as shown in this thread where the modified driving I was doing was again modified in light of newer (better) information.

.

[Diesel_Dave]

Welcome! As a Cummins guy, I probably should take a shot at the new Ford guy, but I'll be nice.

If you've got a detailed aero question Phil Knox, a.k.a aerohead, is the guy to ask. I'm not an aero expert, but I'b be inclined to get rid of the tall cap if you don't need it. A lower cap would definitely be better than the tall one. Lower vs. tonneau is debatable, depending on the dimensions of the boat (consider putting some pics up for us). My first inclination would be to go for the tonneau, or an aerocap (in the ideal world).

My opinion is that a belly pan is preferrable to an air dam, however, it's much more work. I have yet to do mine.

Overall, driving modifications are almost always where the biggest gains are. That being said, you won't have as many options with an automatic tranny.

[Ed-in-Maine]

Thanks Diesel_Dave et. al.
I have weeks of information to dig through. Already some of my long set beliefs are being chipped away. Just for reference, my last real interest in cars as more than a toaster was 20 years ago when I raced SCCA IT RX7. So I'm shocked when I read "Over inflate tires". I suppose tire tech has changed radically. I still have the pyrometers for checking tire surface temps and over inflation as well as under lead to all kinds of nasty results. IIRC we were running radials but they still would bulge wear out the middle and get skittish as hell.
Ed