Chevy Colorado and great gas mileage don't go together!

[91CavGT]

Hi everybody!!

These intros are always kinda weird.


Anyway, my daily driver is a regular cab 2006 Chevy Colorado with the big block 4 banger (2.8L) and a 5 speed manual transmission. I live in the Dallas/Fort Worth metroplex and I drive approximately 100 miles a day. Currently I am spending approximately $250 a month in gas!! I have owned Geo Metros in the past (one had a built up cylinder head on it!!) and recently I am considering getting another one, but first I want to see what I can do with my truck.

On the highway my record on a 120 mile trip according to my Scan Gauge (the original!!) was 34 mpg! Average though is around 28-29 mpg highway and about 23 mpg with mixed driving in the D/FW area.

The only modifications to the truck that I had to get this gas mileage is a drop in K&N air filter, a Dynomax Super Turbo muffler, and a homemade ram air intake (good for 0.25 psi increase over ambient pressure in 5th gear at highway speeds and full throttle).

After reading on here for a bit, I have decided to do a few things to try to increase the gas mileage. I just blocked off the front grill of the truck with duct tape(from the back side so it doesn't look too bad), but there is still air flow coming from the front bumper area(two holes in it with a factory deflector redirecting air to the radiator).

I've been thinking about acetone and a switch to turn off the fuel injectors too, but I want to do one modification at a time to see what works and what doesn't.

[bones33]

Welcome to Gassavers! Your mileage is pretty good actually for a small truck.

If you do mostly freeway driving with your long commute, the biggest gain for an add-on would be a smooth undertray, that's the next step for my Ranger. Trucks are notoriously horrible aerodynamically underneath and get lots of airflow. By the way in my unscientific testing, a smooth tonneau cover offered only a very slight, like maybe .5 mpg increase. If you want one anyway to conceal storage it's great, just get one that is easy to remove to use the truck as a truck. If you're considering it purely for FE, it's not cost effective.

[91CavGT]

Originally Posted by beatr911

Welcome to Gassavers! Your mileage is pretty good actually for a small truck.

If you do mostly freeway driving with your long commute, the biggest gain for an add-on would be a smooth undertray, that's the next step for my Ranger. Trucks are notoriously horrible aerodynamically underneath and get lots of airflow. By the way in my unscientific testing, a smooth tonneau cover offered only a very slight, like maybe .5 mpg increase. If you want one anyway to conceal storage it's great, just get one that is easy to remove to use the truck as a truck. If you're considering it purely for FE, it's not cost effective.

Thanx!! I actually was considering a tonneau cover but I wasn't sure how much it would actually help. I'll have to get my truck up on a lift at school to see how hard it will be to make an aero undertray.

[brucepick]

However a tapered cap like Phil Knox's pickup would probably make a big difference. I know I've seen links here; just do a search.

And I second the underbody aero smoothing. I smoothed the front underside on my car. I did that at the same time as a lowered front air dam and tire pressure boosted from 35 to 39 psi. All three together got me a real increase in distance and speed of coast/glide. So far I've only gone back as far as the front axles. I hope to cover more when I can give it more time.

I used 5.5 mm. lauan plywood for the undertray. At maybe $15/sheet I'm not worried about it holding up. Probably will hold up fine anyway; it's protected from rain and gets plenty air flow for drying.

[BearDog1957]

Welcome. (I'm new here too)

Not being mechanically inclined, I've found that just changing a few habits has helped me improve my FE. Although I still see some arguments against it, I coast in neutral (engine on) as much as is reasonable. So far, I've seen no ill effects on my '99 Camry.

I used to drive with my windows open almost all of the time. Now, I keep them up and use the vent, fan, and A/C, as needed.

I also have a long commute (130 miles daily round). Missouri Ozarks are good for hills, curves, and farm machinery (not to mention the occaisional large animal). I have to watch my cruise control closely to keep it from down shifting.

These are just a couple of helpful hints from here that I've benefited from.

Good luck!

[91CavGT]

I also forgot to mention that I have narrower tires than stock. 225/70/15 were stock, but now I am running 205/75/15 tires.


From watching my Scan Gauge I have figured out the best driving techniques. Putting it in neutral and coasting, accelerating going down hills only, and maintaining constant gas pedal pressure while going up hills are just a couple of the techniques I use.

[Hockey4mnhs]

switch cars with the wife!! and you could get that up to 50 mpg!!

[91CavGT]

Originally Posted by Hockey4mnhs

switch cars with the wife!! and you could get that up to 50 mpg!!

No, I can't do that! When we got married I made a promise to her that I would not touch her car accept for routine repairs and regular maintenance.

If I can't get my truck to get 30 mpg mixed then I'll end up getting another Metro. I've owned 2 in the past so I know for a fact that I could get 50+ mpg out of one!

[VetteOwner]

i hate to say it but ya shoudla gotten a 98+ s-10 the predicessor to the colorado. people have gotten near 38 highway speeds and i get about 27 mixed in my 95 2.2L 5speed (98+ had a head change that allowed even better mpg)

but still, that is pretty good for a truck. if its like the s-10's putting an Efan on it will help alot.

[91CavGT]

Originally Posted by VetteOwner

i hate to say it but ya shoudla gotten a 98+ s-10 the predicessor to the colorado. people have gotten near 38 highway speeds and i get about 27 mixed in my 95 2.2L 5speed (98+ had a head change that allowed even better mpg)

but still, that is pretty good for a truck. if its like the s-10's putting an Efan on it will help alot.

I originally wanted an S-10, but I got to looking and test drove one and the power was not as good. I do some towing on occasion so power was important. I guess I'm wanting to have my cake and eat it too.


I looked at e-fans yesterday. They do help! Even though this has a clutch on the cooling fan, it still spins when the motor is running thus taking power to turn the fan, even at highway speeds.