Tow Vehicle - Gas Mileage

2008 Dodge Quad cab P/U with hemi, 16-18 on the freeway by itself, 13-15 pulling a loaded 6X12. Used to pull with a jeep cherokee with a 4.0L straight 6. It got 18-20 on the freeway, 13-14 pulling the trailer. The jeep struggled up the hills, the truck hardly notices there's a trailer behind it.

 

I was fully expecting the mileage to suffer with the tall trailer. What shocks me is HOW MUCH it suffers. 8-9 mpg at 55 mph, to me, sounds absolutely ridiculous.

From what I understand, a truck also wouldn't be that much better, unless it's a diesel, which will suck gas the rest of the time.

The reason why I was considering a switch was the van is getting old and I don't want to spend repairing it if I'm going to have to change fairly shortly anyway. Plus I don't feel like having break downs on my way to the track...

On gearing, which is best? I assume on the van I'd need to go shorter. On a 5.4 truck, which would yield better mileage pulling the trailer in the wind? Lower (3.55) or higher (3.73 or 4.10). Is there data out there helping to determine the range in which the engine is most efficient?

 

I have no data.
My 5.4 Screw with 3.73 will pull the 7x15 tandem Vnose with 2 racebikes, pitbike, genny and it will lock up the overdrive and stay there as long as you keep it above 75mph. Below 75 it will hunt and I then switch off the OD.

on a 'cannonball' trip to Colorado last year I ran numerous back to back tanks of gas while checking gas mileage, it makes NO real difference if I ran 75-80 in OD or 65-70 with OD off. Either way, 10 mpg is about as good as it gets with a gas V8 motor. My truck averages about 15-17mpg when not pulling a trailer

 

10 mpg, or a difference of about 1 mpg with my sucky van? Looks like the sucky van is here to stay.

 

Just FWIW, i drove about 650 miles yesterday and today in my Edge towing the 5x8 enclosed with one bike in it.

Over that 650 miles i was averaging 15.7mpg.

 

1984 chevy van\ 10mpg.

 

I find it strange how everyone seems to think diesels suck back the fuel equally even when unloaded (or within a few mpg). For reference, we use a 2005 Duramax 2500, in Canada where our gallon is 4.5 litres compared to your 3.8l. (My mpg numbers will be better than yours because my gallons are bigger!)

Unloaded, driving just under the magic 2000rpm range (before the turbo really works) at about 60mph, we get 28mpg and if we slow down to 50-55 it's up to 33-36mph. But if we go up to 75-80 then it drops to 20mph.

With a light load in box and small trailer, our mpg drops by 5 across the board.
With our 40' 5th wheel driving 75-80 or more is dumb as we need to stop for fuel every 2 hours at 7-8 mpg. Slowing down to 60, we get 15mpg and at 50, 18-20 depending on wind direction (heading west always sucks!)

Driving the diesel truck (without a lead foot) actually costs less for fuel than several cars we own as usually diesel is about 7-10% less expensive to buy where we live.

And we've had gas trucks and the difference we've saved on fuel over them has probably paid for itself over the course of a few racing seasons...but we travel a fair bit (100,000 miles per season)

Rick

Rick

 

Diesel ain't cheap in the US. Almost the same price as premium gas.

 

mY '06 GMC w/ 5.7 liter gas engine, 2500HD crew cab got 14 mpg and 8.5 mpg pulling a 34 foot 5th wheel. In the process of buying a 2011 (yes '11) F-350 with the new diesel engine....I'll never recoupe the extra cost through fuel savings but I'm hoping to have a much easier tow.

 

My '08 Avalanche pulling my 7x12 enclosed trailer gets about 3mph.

I just can't figure out why it doesn't do better.

 

I'll test-drove an avalanche a couple years back while looking for a replacement for my F150. The MPG gauge pretty much killed the avalanche as an option- seeing 6-12 MPG averages on the short drive scared me off really quickly!

 

...but it is cool when im coasting down hill and see the 99mpg illustrated.

It makes up for the 3mpg moments.

 

You have a flat tire, and are in 1st gear. :up: You're welcome. ahaha.

 

Actually, the tire pressure monitoring system is disabled, hence the light.

...and i was on the intestate, pedal on the floor, passing people going uphill through the mountains of NC. :up:

 

I've driven the 3.55 and the 3.73. The 3.55 is great for light loads and highway MPG, however if the load increases, wind resistance increases it will shortly become a downfall. The 7x14 enclosed is right on the edge of what would be considered a "light load". I changed the rear gear to a 3.55 on my 2500 and ended up in trouble when I got the big trailer. It kept burning out clutches.

If you're primary use is highway, empty or light load, then the 3.55 should do you well though.

If you plan on towing with a load regularly. The 3.73 is a great gear. My 05 F250 has the 3.73 and I pull a fully loaded 8 x 24 at 70MPH no troubles.

Either way, go diesel. Although I'd wait for the new Scorpion diesel coming out later this year. Supposed to be much better than the 6.4. If buying used, get a good 04+ 6.0 that's had the heads recalled already. The 6.0 will get you 11-14 towing and 16-18 empty.

JMO, good luck whatever you decide.

 

2003 silverado 2500 HD extra cab, 4X4, 5 spd automatic, 4:10 gears, diesel 6.6.

gets 20-22 empty, 18 towing 14' enclosed. (summer, drops about 15% winter)

 

I think you are just asking too much from the 4.3L in your van. It's a big V6 but the extra tall trailer is killing it. I've been through this, my trailer is a 6x14 single axle that is 6'5" floor to ceiling.

My .02 cents would be to look for a full size truck or van with a V8. A diesel would be overkill for that trailer. Would it be nice, sure but it's not needed.

I've towed my trailer with a '77 Buick Lesabre (not good), '84 G10 (3.73 and ZZ3 motor) (good), '96 E150 351w 3.55 (good), '05 Silverado 5.3L 3.73 (very good), and now a '03 E150 4.6L 3.55 (good but no OD)

 

Has anyone here tried using one of those air deflectors for a tall trailer? That might help? No?

 

I've used one with my '77 Lesabre and the G10. I'm sure it helped on the Lesabre but not so much on the van.

 

I have an 03 avalanche i tow a 6x10 with 2 bikes from chicago to gratten
its a flat drive as in no hills but i get 12-13 mpg my friend has a 05 dodge diesel ram he gets 18mpg i dont think its worth 10,000 extra for a new truck for a trailer that small 10g buys alot of gas