Tonneaus

I have had three covers and a topper over the years. recently I put the question on here as well for recommendations. I ended up getting an EXTANG TRIFECTA tri fold canvas and I love it. Mileage I don't thing changed, but like most I bought it so I could tow the 5er and after unhooking have the back secure. In 1994 I put a roll up on my then new Chevy pickup and actually think I did have an increase in mileage, but I hated the roll up. Next I had an Undercover hard cover. It did the job but I didn't tow a 5th wheel back then. Now there are many options, and prices. I wanted to keep the cost down so opted for the soft cover. We just had a very severe rain with high winds for two days and not one drop of water in the truck. I actually installed it in 5 minutes right out of the box.