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improving MPG HELP!

PostPosted: February 19th 2011, 8:15pm
by fcglenn22
Just check my first MPG and it was a disappointing 15.3 mpg

its a 2004 Astro AWD 138k miles

I am sure there are tips on the forum but I could not find too much info if someone could help me out that would be great.
i am not too mechanically savvy so I cant make tricky mods but is there anything that a non "car guy" can do other than proper tire inflation, easy on the pedal etc?

Thanks
Frank

Re: improving MPG HELP!

PostPosted: February 19th 2011, 10:18pm
by Leeann_93
Standard tune up (cap, rotor, plugs and wires) with quality parts always helps.

Re: improving MPG HELP!

PostPosted: February 19th 2011, 11:00pm
by 88astroLT
put some STP Oil Treatment found in the LAP after every oil change. then after a while you mpgs will get better. I am not going to garrantee this but it works for my 97 and my 88

Re: improving MPG HELP!

PostPosted: February 20th 2011, 12:46am
by throrope
fcglenn22 wrote:Just check my first MPG and it was a disappointing 15.3 mpg

its a 2004 Astro AWD 138k miles

I am sure there are tips on the forum but I could not find too much info if someone could help me out that would be great.
i am not too mechanically savvy so I cant make tricky mods but is there anything that a non "car guy" can do other than proper tire inflation, easy on the pedal etc?

Thanks
Frank



Sorry, but not much you can do.

While some get better with RWD & 3.23 rear, our '94 AWD with 3.73 rears does about the same on the highway since we bought it new even though it was rated 15 city/19 hwy. Our '06 Trailblazer with all aluminum V8 that turns off four cylinders when power isn't needed gets the exact same and the EPA rated it 15 city/20 hwy. Recently EPA aligned rating with habits like running the AC and all mpg's dropped. At fueleconomy dot gov you will find the Astro AWD revised to 14 city/17 hwy to accommodate the new standard. Since even the 3.6L Traverse is rated 16 city/23 hwy, I expect reality dictates so much gas is needed to move so much metal.

Another ugly is ethanol. Ethanol has a lower heat value or energy content (76100 BTU) when compared to a gallon of gasoline (114100 BTU). Or in other words, that 10% ethanol mix at the pump costs us in mpg's and we're going to 15%. I also doubt that slice of magic made it to the revised EPA ratings.

If its any consolation, I ran the total $/mi numbers enough times to see if that fifty cents a mile reimbursement pays and always found that the biggest cost was the vehicle purchase price. Since these trucks run forever, the mileage isn't as big a bite as it looks.

Re: improving MPG HELP!

PostPosted: February 20th 2011, 1:33am
by Thunderball
This might not be related here...but its a try. I had some problems with a dirty MAF Sensor and my thermostat causing my SES light to come on. I cleaned out the MAF and changed the thermostat, both of which have an effect in your mixture and fuel mileage, more or less. My SES light went off, but my mileage was pretty bad, 15 City, normally got around 17-18. Since my SES light was off, I thought everything was fine. Then, one day, I disconnected the (-) cable and 'reset' my emissions computer. Took it out for about an hour highway ride. And, my mileage jumped back up a bit. About 18 City and close to 20 Hwy if conditions are right and I don't leadfoot it.

But, I think resetting your computer may cause it to retrain itself and clear out any conditions caused by previous SES light conditions...I'm only guessing. Of course, a good tuneup and always run good gas, Marathon, Speedway, Sunoco. Stay away from any of that alcohol stuff.....blahhhh.. BP, Clark, Shell etc.

Good Luck.

Re: improving MPG HELP!

PostPosted: February 22nd 2011, 7:18am
by a2l1
As vehicles get older the miles per gallon tends to drop but that is mostly due to wear of the components so the posts with the "do a tune up" are correct there. Check the vacuum hoses as well. Just replacing the worn (read old) parts will help but anything short of a major rebuild with fuel mileage in mind ( cams,etc) wont make much difference in the rated mileage. Dont forget you are turning an extra differential, driveshaft,etc so that all wheel drive will cause friction and friction ( and the extra drag) will cost you in fuel consumption. Your mileage isnt miserable so you may want to keep in mind the cost to return. If you increase one mile per gallon but have to spend fifty bucks to do that think of how many miles you will have to drive to get that money back let alone save any. Normally an older paid for vehicle is a much better investment even with worse gas mileage than a newer 30 mpg one that has the monthly payments for the next several years. Some of the new vehicles get only 15-16 mpg so you arent really doing bad. The short answer though is no not much you can do without involving a mechanic, since you arent mechanically inclined and cant do it yourself. :cry:

Re: improving MPG HELP!

PostPosted: February 22nd 2011, 7:02pm
by 88astroLT
Thats completely right A J, Also, the computer, dont rely on it, because its just estimating after every fill up, just calculate it then. Both of my vans dont have the computer just a compass and temperature. Also, for those who are wondering if they have a computer, it only started in 1998 vans equipped with the overhead console.

Re: improving MPG HELP!

PostPosted: February 22nd 2011, 10:27pm
by Phantom
The computer gets it's reading /calculations from the VSS which is calculated according to the range of tire/wheel combo up to the maximum factory allowable tire diameter , the vehicle speed changes the instant mpg readings , other readings are based on prior data stored and how many gallons have been used . Resetting the overhead trip computer may help show updated readings , as I did not have the overhead trip computer when I bought my van and I installed one from another van and it still had the reading from the van it came from ,it was showing in its history the gallons used when it was installed and I had not even driven it but just a few blocks but showing many gallons used ,after I cleared the trip computer it show zero gallons used

Re: improving MPG HELP!

PostPosted: February 24th 2011, 5:20am
by Thunderball
Hey AJ....right on though. I know I complain about 16mpg now, but my van is paid for! I had figured out that my previous leased car, a Chrysler 300, with it's payment and gas was a fortune. So, with my paid off Astro, gas would have to be 9.50/gallon to equal what it was costing me to run that 300 with its payment and fuel. And, Astro's insurance is dirt cheap with a good driving record!!!

Oh, I see a couple of computer comments above. If it's referring to my post above that about resetting the computer, then it may be confusing. I was referring to resetting the engine's emission computer....the SES computer, not the overhead console.

Cheers.....