Towing with a V-10

[pappy19]

We are on an extentened trip from Utah to Florida with a 2 week stay in Mesa, Arizona. We hauled from Bountiful, Utah to St. George and the next day from there to Mesa, Arizona. Lots of long hills and seems like more up-hill than down-hill. Average speed was 65-70 with a few up hills down to 60. I passed a few diesels and one 6.0 passed me hauling a small 16' utility trailer.

Total miles to Mesa was 722 and average mileage was 8.4 actual. Lie-O-Meter said 8.9. I used the mid-premium gasoline as most were 85 octane and my programmer doesn't like anything below 87. My CEL came on about half way through the second day going up the long hill out of the Grand Canyon bridge. The day after we made it to Mesa, I went to a shop to check the code and the CEL light was off. Code said it was a stuck EGR but must have cleared. Engine never did anything funny and I never backed off. AS is towing nicely and we are still liking our SO.

[loudruff]

Consider this cause: With our 5.4 engine when we first towed we got a similar light which soon cleared when we quit towing. Check indicated bad EGR, We replaced the EGR and the next time we towed same problem. We installed a vacuum guage and found that when pulling a grade engine vacuum dropped to near zero long enough to trigger check engine light. We also changed the vacuum operated switch to the computer. Now we drive with a vacuum guage mounted on the dash. It is surprising how quickly the engine vacuum drops when pulling a grade, especially if you keep your foot in it. Without degrading engine performance Now we only tow in haul mode and watch the guage.

[DKB_SATX]

Manifold vacuum drops when your foot is in it because the throttle is wide open, with less restriction the engine is creating less vacuum.

Have you noticed that Tow/Haul allows the engine to tolerate this low-vacuum condition without setting the CEL, but pulling wide-open in "normal" mode sets the light? That would be an interesting computer trick, telling the computer to assume it's just a full-power situation in Tow/Haul but assuming it's a problem in normal mode.

[pappy19]

I was in the tow/haul mode the whole time, but when the CEL went on, my foot was to the floor. It was 1/2 way up a long hill and I had to back off 3/4 throttle to let a slow mover pass a semi. When I got past the semi and slow mover, I had to punch it to get up to speed again. Nice to know others had a similar experience, but relatively harmless.

[au_ee]

I noticed a Kubota 900 UTV in your sig line. I assume this is a typo and meant RTV. We're thinking of buying one to use on some acreage we have in TN. Are you happy with yours? Any options we should consider?

[pappy19]

Originally Posted by au_ee

I noticed a Kubota 900 UTV in your sig line. I assume this is a typo and meant RTV. We're thinking of buying one to use on some acreage we have in TN. Are you happy with yours? Any options we should consider?

Yes, the 900 RTV. I added a few options: Curtis Cab, extra lights, wipers, winch, bed liner, and most important, the snorkle air cleaner setup. The factory air cleaner is nearly on the ground and is a bad dust collector. By putting it up behind the cab, there isn't much dust. I gutted the spark arrestor as well. It gets almost 80 mpg and runs great. Not fast at 28 mph, but I don't need to go that fast around the woods anyway. They make an 1100 with a factory cab, AC, etc, but it has alot of extra weight and I don't like the way the doors open compaired to the Curtis Cab doors.

[4RXLA]

Good to know about the CEL as i am heading for St. George next month for a 3 week grand circle tour and expect to encounter lots of elevation changes. I expect my V10 to get quite a work out and will be happy with 8.5 mpg if I can get it. I take it you have an aftermarket tune?

[pappy19]

Yes, I have had a DiabloSport Predator($275) installed since the truck had 5,000 miles. I have kept it on the tow/performance "middle" setting which is supposed to take 91 octane. I have found that 88 will work fine but nothing less. If I wanted to go for mileage, I would drop it to the 87 rating which would probably let you use 85 but never tried it. My wife's 2007 Lincoln LT with the 5.4 has a Superchip in the high performance mode and it runs very nice as well. I bought the Predator as it was the first company to have a programmer for the 2008 V-10 in August of 2007 when I got the truck. I also added a $300 Airaid intake system and $300 Magnaflow exhaust system with resinator delete. I run strictly Chevron Delo dino oil, not synthetic. Since my F-250 is not a diesel the rear end dif was not finned so I added the Maghytec dif cover with larger capacity and finned for better cooling. I love the TorqueShift tranny but still added an external spin-on tranny filter @ $40 from Summit Racing to help cooling and easy maintenance.

[pappy19]

I did the actual calculations for my towing portion of this trip so far: 2162 miles and used 256.6 gallons. Comes out to a little over 8.4 mpg. The dry weight of my Airstream is 9100 lbs, so with water and all of our crap, I know it's got to be close to 10,000 lbs.

My solo mileage was 1589 miles and 169 gallons = 9.4 mpg, but that was doing 85 and sometimes headwinds and lots of hills or stop/go in California traffic. I usually get around 11 with my lead foot so this was somewhat below my normal.

Pap

[4RXLA]

Pap,

your mileage figures are exactly what I am getting towing and solo w/lead foot. Last weekend I towed the AS home from the repair shop (120 mile trip) and had a 25-35 mph tailwind all the way and got 11.3 towing. On the way to pick up the AS doing 85mph into the headwind I got 11.

[pappy19]

See my post on the "On the Road" forum.

Pap

[RamblinManGa]

Hi from Ga. . . My '08 F250 FX4 w/ V10 got about 10.5 to 11.5 on two extended trips. Oh well,but what troubles me is that I only get 11.5 without the 7000# trlr behind. That doesn't seem right. May go to a Banks kit in the future., Regards, Craig

[pappy19]

We just got back to our temp spot in Bountiful, Utah after going a total of 7,996 miles, of which about 1200 were solo miles. Total gasoline used (mostly 89 octane) was 936.3 gallons, which equates to an averave mpg of towing/some solo = 8.2 mpg. I have to say that a few of those days towing were horrendous headwinds, especially from Weatherford, TX to Las Cruces, NM on 4/13.

Our 30' Classic/SO worked without a hitch. Even with the bad headwinds, I had no real problem save a few really bad gusts. Our Equal-I-Zer hitch worked great along with the Firestone air lifts which definately helped to keep everything steady.

Finally, our 2008 F-250 V-10 was a seasoned champ passing 89,000 miles and never had a hicup pulling mountains, Arizona heat, and terrible headwinds. Best truck we have ever owned, without a doubt.

Pap