Should I go with the recommended tire PSI (29 front/32 back on my DC), or bump them all up to 40ish?? I think they were set around 34 or so on the trip.
I've experimented with tire pressures on many of my vehicles and I noticed several things....
When increasing Tire Pressures drastically(40-50 PSI)
PRO - Better Fuel Economy
- Better(crisper?) steering reaction
- Less Tire Noise
CON - Less traction(Braking requires traction)
- Stiffer ride/more pronounced bumps,RR tracks, potholes etc.
- Shorter tire life/uneven tire wear
- Increased wear on other components(Hard to quantify, but across three vehicles I had more problems while having overfilled tires.......My reasoning is probably that the tires are a major factor in the stiffness of your suspension, and most vehicle components don;t like harsh bumping)
In the end, after I had my children, I could no longer come close to justifying the loss of braking traction to save some MPG, and I also found that if you put money into good tires, it's not worth overinflating due to the shortened life of tires clawing back that small savings.
The situation where it made sense for me was my long 86km per day drive to work on highways with no traffic, and el-cheapo tires on my vehicle.
Not that my 2 cents is worth much(we don't use pennies in Canada anymore), if you want an increase in fuel economy, I would recommend purchasing very good tires with low rolling resistance(I'm a michelin fan, think green X).
Along with that, my best fuel saver mods are:
-Clean out the box or trunk to remove excess weight, every pound counts.
-Clean out your throttle body and butterfly valve
-Purchase a small fire rated insulation blanket and wrap your air intake tube, keeping the air as cold as possible from the filter to the engine
-Use a higher flow air filter (comes with MAJOR downsides, but will increase your fuel economy)(I personally use factory)
-At the next Oil Change, ensure you are using a high quality SYNTHETIC oil that is viscosity rated appropriately for your predicted temeratures
THE ABSOLUTE BIGGEST ONE>>>>> Accelerate from a full stop like their is a child walking in front of your truck, and set your cruise control at the slowest safe speed you can go, and NEVER EVER let it idle in a parking spot for more than what is necessary to warm your engine(about 1 minute). You'll be amazed at the difference in fuel economy when you do this! I experimented in hyper-miling when I had a very old Nissan King cab pickup, and I managed to increase my fuel economy about 20% based on different driving habits.
Best of luck, hope any of this helps!