I'm new Here. fuel efficiency problem.

Hello all,

I want to introduce myself and ask for some advice. I'm a landscape photographer in Phoenix, AZ. I use my 02 tacoma for what it was made for. Bought it at 50k in 2005 and now have 228k. We've been all over the Southwest deserts, including many trips to remote stretches of Sonora and Baja, Mexico. I'm not in this just for the thrill of rough trails, but to get to the best places I can, to make photographs and be in wild country. Best truck I've ever owned.

On to my issue: My standard mpg as been 20 since I owned this truck (fully loaded with camping and camera gear and traveling companions). Sometimes I can pull up to 23 but never get below 20, ever. So I started to average 18-19 last summer. My mechanic (sorry I'm not that handy with repairs!) thought it must be the fuel mix that shifts in the summer to more Ethanol. Of course, my truck never showed signs of this in the past 8 summers.

Long story short I'm still getting bad mileage and last tank was 17. The tank I'm on now looks like its getting even worse.

this summer : replaced the spark plugs, decarbed the throttle body, ran a few tanks of premium through it. fuel filter just done last week.

Any help would be appreciated. Should I replace O2 sensors even though mechanic says the 02 levels are ok, and without a check engine light on?

I'm leaving for a week long trip to Baja on Sunday and don't expect to resolve this before then, guess I'll bring along a couple jerry cans.

Thanks !

 

Possibilities:

Partially blocked cat converter
Low compression in one or more cylinders
worn fuel injector(s)

 

I average about 17-19mpg on mine with about 50/50 hwy/city driving.

Just a thought but are your tire pressures up to spec? Maybe the diff wants some fresh oil as well.

--Dan

 

Thanks for the replies. Tires are at 40. I like 35 better for the ride but added some air to see if it helped. I changed the diff oil about a year ago, and had checked them a few months ago.

I hope its not the cat, low pressure or the injectors, but will check them next.

Might just change out the upstream sensor just to see. I've never changed the sensors before and 226k is about time I suppose.

 

Clogged intake or filter maybe. Does it run different that you can tell?

 

One of two differences I've noticed in the past year or so: the idle can sometimes be inconsistent. When I come to a stop, the idle takes a little longer to drop back down to just under 1k.

When its cold ( and this is Phoenix, so not below freezing ) it has a little bit of hesitation starting up in 1st, if I'm really trying to give it gas. If I ease into like a gentle driver, no problem. This goes away when the truck is barely warm.

Other than that it runs just like the day I bought it. Just as much power and no noises.