Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Filling oil just to min line? better mpg?

Fr3AkAzOiD · 12-31-2009, 10:38 PM

I have read around here though I can't remember exactly where that some people have gotten mpg gains by just filling their cars oil to the minimum line instead of all the way up to the full line on the dipstick.

Anyone have any info on this?

I don't exactly see how you would get better mpg cause I would assume the oil pumps at a consistent rate/pressure regardless of oil level in the reservoir.
Now I know that the oil does cool down while in the reservoir so unless the slightly warmer oil has something to do with an increase in mpgs such as lowering it's viscosity. I'm not sure.

Now I am concerned with any negative effects of doing this however I have the feeling the only reason that your oil gets filled to the max line or that there is a max line at all is to (a) Keep people from overfilling their cars oil.
and (b) Since the majority of people don't check oil levels in between fill ups that extra oil is to protect people with oil leaks or cars burning oil from blowing up their engines cause the oil only gets checked once every 5,000 miles. Just a hunch, unless someone knows better.

Now I know in my car the min line to fill line is probably a good 1/2 quart+ and I check my oil regularly so would catch any lowering of oil levels quickly.

Other then the savings of about $2.00 worth of oil with each fill up would there be any increase in mpgs?

Only reason I ask instead of simply looking for any improvement is that I finally started to do my own oil changes and with my first change switched out to Mobil 1 0W-30 Advanced Fuel Economy.

According to it's claims on it's web site's savings calculator vs conventional motor oil I should get between 0.85 (winter) - 1.1 (summer) extra mpg. Will report any findings in a seporate thread.

Added bonus is that I get to use better grade motor oil, quality oil filters made in the USA instead of the cheapest ones the shop could get it's hands on. I also save $5 per oil change by doing it myself even with paying the premium of higher grade products. I also get to get away from the wife and munchkin and pull out my old box of cassette tapes and blast them in the garage for an hour.

BTW, heated garage FTW!

12-31-2009, 10:38 PM	#1 (permalink)
Fr3AkAzOiD Ecomodder Join Date: Jul 2008 Location: Raleigh, NC Posts: 259 Cobalt XFE - '08 Chevrolet Cobalt XFE Team Chevy 90 day: 41.1 mpg (US) '05 Malibu V6 Tow Vehicle/Track Car - '05 Chevrolet Malibu LS V6 90 day: 23.12 mpg (US) '08 XFE average for 2013 - '08 Chevrolet Cobalt XFE 90 day: 41.1 mpg (US) Thanks: 41 Thanked 25 Times in 20 Posts	Filling oil just to min line? better mpg? I have read around here though I can't remember exactly where that some people have gotten mpg gains by just filling their cars oil to the minimum line instead of all the way up to the full line on the dipstick. Anyone have any info on this? I don't exactly see how you would get better mpg cause I would assume the oil pumps at a consistent rate/pressure regardless of oil level in the reservoir. Now I know that the oil does cool down while in the reservoir so unless the slightly warmer oil has something to do with an increase in mpgs such as lowering it's viscosity. I'm not sure. Now I am concerned with any negative effects of doing this however I have the feeling the only reason that your oil gets filled to the max line or that there is a max line at all is to (a) Keep people from overfilling their cars oil. and (b) Since the majority of people don't check oil levels in between fill ups that extra oil is to protect people with oil leaks or cars burning oil from blowing up their engines cause the oil only gets checked once every 5,000 miles. Just a hunch, unless someone knows better. Now I know in my car the min line to fill line is probably a good 1/2 quart+ and I check my oil regularly so would catch any lowering of oil levels quickly. Other then the savings of about $2.00 worth of oil with each fill up would there be any increase in mpgs? Only reason I ask instead of simply looking for any improvement is that I finally started to do my own oil changes and with my first change switched out to Mobil 1 0W-30 Advanced Fuel Economy. According to it's claims on it's web site's savings calculator vs conventional motor oil I should get between 0.85 (winter) - 1.1 (summer) extra mpg. Will report any findings in a seporate thread. Added bonus is that I get to use better grade motor oil, quality oil filters made in the USA instead of the cheapest ones the shop could get it's hands on. I also save $5 per oil change by doing it myself even with paying the premium of higher grade products. I also get to get away from the wife and munchkin and pull out my old box of cassette tapes and blast them in the garage for an hour. BTW, heated garage FTW! __________________ Lifetime mpg 2012 mpg Last edited by Fr3AkAzOiD; 01-01-2010 at 06:56 AM..