Chevy Colorado 5 cyl - improve mpg

[skiprocks]

Greetings group
I just found this group today and would like to ask for your input. I have a 2007 Chevy Colorado with the following specs. L5 3.5L - 5 cylinder inline 5, Automatic Transmission, Crew cab, 2WD, Leer cab height camper shell. I put way too many miles a year on this thing (35k+) a year to drive, but it's job related and can include a lot of gear in the back, up to 4 people, and a trailer now and then. So this vehicle fits my needs pretty well. Also, recognize that I'm a recovering 1-ton, 4X4, dually kind of guy (2 year pin).

With a light load and no trailer I see 24-25 mpg on the hiway. If I focus 100% on mpg and never drive above 65 (no passing either) I have seen just over 26. But suffice to say that if I watch myself, I can get 25 on the interstate.

Anyone been doing anything that can give me more mpg? I was looking at the K&N air filters, but they don't seem to show improvement in hp until over 3000 rpm, and I'm well below that (2000 rpm) when holding 65 on the interstate.

Any other thoughts? As for the truck, I like it. I bought it based on price (cheap), and selected 2WD for fuel economy as well. In two years I've really needed 4WD maybe a half dozen times. I like the larger engine for those occasions that I do tow. I towed my Jeep CJ-5 from Virginia to Colorado and honestly didn't notice any lack of power anywhere along the route.

Thanks - Skip

[theholycow]

You're right about the K&N. Most intake and exhaust products can't help someone who drives for fuel economy, since such people tend to keep their RPM low -- and if the system was restrictive at low RPM then the engine wouldn't be able to get to high RPM at all. Therefore, the stock system, which supports making decent power at high RPM, must flow very freely at low RPM.

The most important nut to adjust is the one behind the steering wheel. That's in someone's sig and it's very true. You can read all about fuel saving driving strategies here.

There are some modifications that can be done, but most are not cost-effective. Start with tire pressure. Read the link in my sig about tire pressure. In short, you should probably be running a lot higher pressure than you currently do, and no it won't cause tire failure or any of the other bugaboos often feared.

[skiprocks]

> The most important nut to adjust is the one behind the steering wheel.

You've got that right in my case anyway. If I "want to" get 20 mpg and drive like an idiot I can certainly do that. But I chose this truck because it did get good (fair) mpg given the needs that I have and I'm fully aware of the cost of both a lead foot and what some might call aggressive driving techniques. So given the fact that I'm working on the wing nut behind the wheel (and running 40 psi air pressure)... what else? :-)

[thornburg]

Originally Posted by skiprocks

> The most important nut to adjust is the one behind the steering wheel.

You've got that right in my case anyway. If I "want to" get 20 mpg and drive like an idiot I can certainly do that. But I chose this truck because it did get good (fair) mpg given the needs that I have and I'm fully aware of the cost of both a lead foot and what some might call aggressive driving techniques. So given the fact that I'm working on the wing nut behind the wheel (and running 40 psi air pressure)... what else? :-)

Check out some of the links in theholycow's sig, and the stickied threads in the Aero mods, experiments, & general fuel economy forums.

If you are primarily driving highway miles, aero mods (like a grill block and/or airdam) might be your best bet for a next step.

[collie man]

i have a colorado but 06 with the 3.5 z71 2wd and i have put a flowmaster exhaust and a k &n intake on it and it did help tremendously. i took the same trip before and after the mods both at 65 with no passing and got an extra 50 miles on the tank

[theholycow]

Got any theories why your intake and exhaust helped fuel economy under light cruising? At a steady 65mph you're not using anywhere near the capacity of the stock systems, which need to flow enough to make maximum power; if they can flow (somewhat restrictedly) enough to make all that power, how could they possibly restrict a fraction of that flow rate?

You were probably using 15% of the power (and therefore, 15% of the intake/exhaust flow) your engine is capable of.

[Jay2TheRescue]

Take a look at my garage entry and gaslog for "The Beast". You'll get some ideas on stuff to try. My recommendation is make sure your tires are inflated, and try a grille block and warm air intake. Also, a Scangauge (~$150) is probably one of the best tools to determine what works, and what doesn't when driving your vehicle.

-Jay