Bad MPG with an 03 Chevy Astro, V-6 2wd...

My mileage has gone from bad to worse, last tank figured out to just under 10 mpg. It is rated at 16 city. I do not idle it to warm up.

Less than 4k miles on the van, purchased at the end of August.

Is it possible that my drive is too short? It is only 4 miles each way to work now. I suspect that it doesn't get warm enough for the ECU to switch into closed loop mode.

My last jobsite was 9 miles each way, and the mpg was better at 15.

Engine, trans and diff are filled with Amsoil.

Any ideas?

You're probably right about the engine never running in closed-loop with a drive that short. I've heard that those vans sometimes have a problem passing emission tests because the catalyst is too far down the exhaust pipe from the engine and it takes forever to warm up ...

Might have to go for a longer run once a week just to give it some exercise. You won't save fuel overall by doing this, but at least it should get less condensation in the crankcase and will keep the battery charged.

How long did you run it with the original crankcase oil before switching to synthetic? Switching too soon can sometimes cause some break-in issues (i.e. it doesn't happen, and the engine has high leakdown for the rest of its life) but I'm not sure how the 4.3 V6 handles this. On the motorcycle engines that I'm more familiar with, you have to do an initial fill with non-synthetic, and then after a couple of heat-cycles at light load, beat the tar out of it for about half an hour to get the rings seated before you change to synthetic.

I changed to synthetic oil at 500 miles or so. The 500 miles was longer drives at varying speeds. The short commute is a recent change.

I am also considering the weekly highway drive.

I have always held the idle up and the heat on at emission testing locations while waiting. Haven't had any problems (yet) with this method.

There aren't any driveability issues / MIL's that would suggest abnormal fuel consumption. I was expecting to lose about 25% - 30% off the EPA ratings during the winter, not the almost 50% that I am experiencing. I don't know if longer drives would help, but I am glad I don't have to at this time.

I have my brother checking into TSB's or anything related to my "problem". He thinks it is "normal".

If this keeps up, I will give the Sprinter serious consideration after 2006. I could deal with 16 mpg once the Astro is paid for (my Ranger got 19), no way I am going to deal with 9 to 12 any longer than I have to. Right now I am wishing I spent the extra money.

I wonder how all these fellow Americans actually drive SUV's that get such bad MPG everyday, filling up every other day. /images/graemlins/eek.gif

<font color="blue"> I wonder how all these fellow Americans actually drive SUV's that get such bad MPG everyday, filling up every other day. </font>

They gotta be makin' big money or in DEEP debt always!

Howdy danski0224,
I live in Tinley Park just south east of ya!
Anyhow,Momma drives a 2000 Astro Van 2/wheel v-6. Travels 'bout 6-7 miles to work each day also.
Again bad milage,mostly stop n go trafffic. I did get her to warm up the vehicle 5-10 minutes before leaving for work especially during the winter months. I do understand that the Astro isn't no "Gas Milage King" this is our "Third one"
but what really bothers me is the rate of <font color="red">Oil Consumption </font>!!! No leaks,or blue smoke ever! No excess fluid levels in trans or coolant,so only thing is it's being consumed and burndt off. I "heard was told" synthetic oils won't "consume/disappear" like conventional "dino" oils.
All three of these owned Astro V-6's consumed oil at what I considered an alarming rate. 2 quarts per 3000 miles??? whether daily commuting (Momma) or highway trips (vacations). So my advice to you is to keep an <font color="blue">EYE </font>on the engine oil level. I do like the Chevy Astro (as said before,this is our third one) but I think that now the kids are older,this will be our last. Gas milage and oil consumption is really bad for something I feel should be alittle better. Heck these vehicles ain't cheap$$$!!!
I am definately on the hunt for a "Diesel" preferably a "mini pickup/diesel when they build and import them again" for my work and a diesel for momma to use for work.
In the mean time,I'll stick with my motorcycles as my main
hobby/interest. /images/graemlins/rolleyes.gif

Welcome to the world of the old school American motor. It's really sad considering that GM makes some wonderful, quiet, powerful, non-oil consuming V-6 and V-8's. The 3800 the 5.7V8 ect. All get good or great mileage. Burn oil? Almost none. I think it boils down to it being a "truck" and their crappy machining and build techniques for that plant making the 4.3L.

Also, I would switch back to regular oil for 3-4K to see if that helps break it in.

Our Cheroke gets 15-17 most of the time. If you keep the speed under 65 you get 21-22. 75 nets you 15. That truck is old school for sure. Intake and exhaust on the same side of the head for cripes sakes. And you want to talk about a POS. I'm glad it's leased. 11 more months. In the last 4 months it's had a head gasket, steering rack, steering gear, 3 injectors, cat, header, 2 bushing kits for the shift mechanism, transfer case, front and rear pinion seals, front and rear diff cover gaskets, diff vents, 3 sets of front rotors, 3 sets of pads, both rear shocks, 2 gas caps, radiator, and both transmision cooler lines.

Sheesh, about $10K worth of work. THANK GOD FOR THE WARRANTY! The truck hit 33K and it just puked. Almost all highway miles too.....So much for D.C. getting the bugs out.

<font color="blue"> Sheesh, about $10K worth of work. THANK GOD FOR THE WARRANTY! The truck hit 33K and it just puked. </font>

Damn right your lucky your just leasing that thing!

I've heard a couple of nightmares from some VW owners too.

I'd still like to rid this "GAS HOG" and get a "DEZZZLE"!!!

[ QUOTE ]
<font color="blue"> Sheesh, about $10K worth of work. THANK GOD FOR THE WARRANTY! The truck hit 33K and it just puked. </font>

Damn right your lucky your just leasing that thing!

I've heard a couple of nightmares from some VW owners too.

I'd still like to rid this "GAS HOG" and get a "DEZZZLE"!!!

[/ QUOTE ]

AAAAAMMMEEENNNNN!

I want a diesel somethingorother. Sprinter......mmmmmmmm....nnniiiccceeee.....Drove one. Sweet. Upsolute that puppy and you are good to go.

Well, at least mine isn't burning oil, but I don't even have 4k miles on it yet (purchased at the end of August 03). I will keep a closer eye on the oil level, though.

If the rumors are true, it will really suck to fill it up this summer when gas hits $3 a gallon. I really hope I am still working close to home. Otherwise, the Jetta is gonna get a roof rack, and the van will stay home unless I truly need it.

The family mechanic basically told me that my milage is considered "normal" /images/graemlins/frown.gif and there isn't a solution. I would have thought there was some way to adjust the throttle tip-in, because it sure seems agressive to me. I find it very difficult to gently initially accelerate from a stop.

I will really be looking at the Sprinter (or similar) in 2006/2007. Hopefully at that point I will be in a position to swing (and justify) it. Couldn't do it this time.

I think the next truck will be the last one- they are getting too damn expensive. Or it is time to buy $2k clunkers and pull the tags when it dies on the road.

[ QUOTE ]
The 3800 the 5.7V8 ect. All get good or great mileage. Burn oil? Almost none.

[/ QUOTE ]
The 3800 is a great engine. My dad's GrandPrx has it. Its quiet idleing, sounds good at full output, and he's able to get 25 mpg on the highway. Not bad for a car of that size. In some of the new Buick adds they say that it gets 29.

He's put 60k miles on that car in one year and it still runs great.

But I still like the jetta more... DAMN SPEED SENSTIVE STEERING! I really hate it, I feel that it makes the car harder to drive. Too easy in a parking lot, too hard on the highway.
[/rant]

-Jason

He's put 60k miles on that car in one year and it still runs great.

One sentence explains it all. And this man is a candidate for a Diesel engine in something (an old 40 mpg VW caddy, eg)

On my Passat VR6, I supposedly run 11 mpg during warm up, then it hits 25 plus when the oil temp is up to 206 degrees.
For runs of less than 5 miles, maybe a bicycle makes more sense; better yet, a VW "One Liter".

Well, thats why he got the jetta TDI. That was his previous company car. It is kinda small whn you need to take 2 customers to an event. Thats why he replaced it with the grand prix. He is looking forward to getting a Passat TDI, even if it will only be available with an auto. trans.

-Jason

<font color="blue"> I've heard that those vans sometimes have a problem passing emission tests because the catalyst is too far down the exhaust pipe from the engine and it takes forever to warm up ... </font>

Hi Brian. Last week I brought "Momma's" Astro in for the Emission Test,and they now test it with "OBDII" computers.
No more tail pipe tests. This test begins with all vehicles 1996 model year and newer. If the OBDII test fails, then they give one more chance, "the tail pipe test". This is kinda nice cuz they can tell you which emission control part is "bad".