Warren I highly recommend them. On my 150 I didn't have anything, when I hit the freeway I'd open the tailgate. I could see a drop in mileage when I didn't. The Avalanche has bed covers standard and I really like being able to lock things in the bed but still have an open bed when I need it. I built my own bed slide for about $45 so I can pull it out and get to things at the back without crawling in or taking the cover off.
If you go with a cover, you might look into something in a flexable cover that can roll up or fold at varying lengths. We have one of those tonnue covers (pardon the spelling) on our Heritage ext. cab and for the most, we love it. Being the hard fiberglass type, it has it's pros AND cons. It looks very good on the truck. It's nice being able to lock it. It opens up far enough to be out of the way for tailgating and getting things in and out. However, it limits how tall things can be in a big way at times. You might also consider a shell for your truck bed. Just food for thought.
Prior to my Avalanche, I had two different pickups. I had a cap (shell) on each. I don't remember the numbers for the Mazda, but on the full size chevy, I would see a 2-3 mpg difference with and without the cap. I will never own a pickup without a cap.
I'd be interested in hearing more about your bed slide. You can PM me with the details so as not to clog up the forum if you'd like.
I have been driving pickups for many years now and have at times wondered if I would like a cap or cover. However, I use the bed of my truck all the time and more often then not a cover or cap would be in the way. How do you handle that situation? Do you have a trailer that you use? I do have 50 acres at home and use the truck there a lot so maybe it's not a apples to apples comparison. I have also used my truck to move furniture on many occasions.
With the Avalanche, removing the cover takes about 60 seconds. With the pickups, my caps were just clamped on, so if I knew I was going to need the verticle clearance, I would remove the cap. They are more awkward then heavy, but are easily managed by two adults. I have removed and replaced mine by myself, but it is a chore.
In your situation, I would recommend one of the soft tonneau covers. These generally unsnap and roll up out of the way. That way, when you don't need the vertical clearance, you can reap the benefits of the increased fuel mileage.
I think it really only becomes a big factor when traveling at highway speeds, but I would only be speculating.
They make some pretty swanky soft covers that roll up now days. If you google on truck accessories you'll find a ton of them, JC Whitney is a good place to start too.
Tim, I'll find the link for the bed slide on the Av club site and PM it to you. I love it. I couldn't justify $500 for a commercial one, but for what I paid its been great and the guy that came up with the design made sure the wheels glide in the grooves of the Av's bed mat. Was a simple mod took me about 4 hours.
I have truely been blessed. I found and married a woman that loves BIG Ford trucks. Therefore, we have two of them. The "nice" truck with the Heritage package and the bed cover is hers. Mine is the Sport model. Plain white with a spray in bed liner. I frequently need the verticle clearance also. Each serve their own perposes well.
A forum community dedicated to Keystone Outbacker RV owners and enthusiasts. Come join the discussion about modifications, travel trailers, 5th wheels, appliances, towing, camping, classifieds, troubleshooting, maintenance, and more!