X15 questions

[Camstyn]

(01-21-2021 )Waterloo Wrote:  

(01-21-2021 )Camstyn Wrote:  I think you’ve got the wrong idea about me. I do keep my speed down, I keeps my boost down never exceeding 20, I run my truck at the 1400-1600rpm range and cruise at 1500. My torque gauge never exceeds around 70% on the steepest of grades. You’re preaching to the choir. I drive for fuel economy, there’s not much more I can do to improve now other than change equipment. I do not demand or use 565/2050, that is just the program my engine happens to have. I drove it with these same techniques when I had the 505/1850 program.

I’n not saying I’ve mastered the driving habits but I have been applying these techniques for years. I just want to know if the efficiency series would actually be more efficient or if it’s just marketing.

I have a different set up, 3:42 gears, 18 speed. Do you use the cruise control or your foot? I am assuming your foot, as you stated you try to keep the boost low, which is how I drive. Rarely the cruise is used, and if it is, the land is flat, I don't use it much other than when bobtail.

The RPM's, @ 60 mph, I run in high 7th @ 1800 rpm, usually when heading into the wind, letting the motor do the work. When in the mountains or very hilly terrain, I tend to run in high and low 7th, or high 6th. Trying to always keep the rpms over 1600 and up to 1900. If the rpms drop below 1600, I can see the fuel mileage on the computer drop to 2 mpg, so I keep the rpm up, in that 1600+ range by dropping and splitting gears, and get 3+ on the computer.

The above is how I get the best fuel mileage in my brick of an aero truck. A mid roof hauling doubles is not very aerodynamic, huge gap behind the cab and trailers, the Herd Defender Bumper does not help, along with all of the crap on the truck, steerable lift axle and APU... 6 mpg is about the best I can do under the circumstances. The saving grace, the truck is paid for, and knock on wood, running fantastically. The Solar Panels saved me quite a bit on fuel too, the APU rarely ever runs, if at all.

Yes I only use my cruise control on sections of road where it won’t be acting any different than my right foot would be doing, like long flat road, or a long gradual steady grade. I’ve been doing this regional linehaul for 11 years so I know the roads like the back of my hand, definitely helps to know how to make the truck work as little as possible.

After reading this I decided to try running up a few hills at my normal speed but a half gear lower, so at 1750 instead of 1500. It did look like my instant fuel economy was lower. I’m going to experiment with this some more next week. I hadn’t really considered letting it rev more because I’m not working it hard at all, and it just doesn’t feel natural but going to give that a go and I’ll report my results after a few rounders.