need a straight answer
 

i need a clean and clear straight answer...
will 5w-20 grade motor oil yield in better mileage than 5w-30 grade during sunny days (summer)?

it will most likely make no difference.... and if it does make a difference it wont be big enough to notice.

use the recommended oil.

clean and straight?

YES.

when would it -not- provide better gas milage?

Yes, you will probably get in the range of of 0.05 to 0.1 MPG better. The real questio is why do you use 5w30? If you live in the desert where it is around 100F every day, the 5w30 is fine. But if you live in area where the average at any point is less then 70F, you should be using 5w20.

man, walmart doesnt sell mobil 1 in 5w-20... mostly 5w-30 on the shelves. gotta pay that exspensive price autozone sells now :_doh:



anyone know if costco sells mobil 1 5w-20 cheaper than your average store?

yes, under identical conditions, 5w-20 will yield better mpg than 5w-30.

were their any testing/expierents done for this comparsion?

Yes I think I owuld like to see that study, no matter what I bet I can find something wrong with the way they did it :hgrin:

Really though, there is little differance once the car is started and warmed up and the oil has been heated between the 5w20 and 5w30, but yes, 5w20 should give a tiny bit better.

there is no study, its common knowledge. or so i thought. i expect that to be debated on these boards, id rather see this discussion on bitog where more people know that this is fact.

Well, yeah, I know that is true, you will get better MPG with lighter oils, that indeed is known. But the differance between 5w20 adn 5w30 is very little. now if we where discussing say 5w20 versus 20w50 or even 10w30, then yeah, there will be a noticable differance in MPG and even power. But these two oils are really close, and when you are talking about synthetic oils, they are even closer because synthetic oils tend to be stay at the same viscosity for longer periods of time. So yes I agree that a thinner oil will give better MPG, but I just don't think these two oils are going to be noticably different.

i agree, the gains are minimal and if people were to try both oils themselves they probably wouldnt notice any difference.

My Wal-mart is getting it in finally (after prodding the department manager and asst. over the auto dept. ) plus my discount makes it about $3.50/bottle or so

do you know if the entire walmart franchise will be supplying M1 5w-20 or is it just your specific area?

varies by store unless it is considered a 'tab' (read : hot selling) item

just go pester them to carry it...thats what I did best thing to do is get them a bottle or the upc of the bottle and tell them you'd like them to carry this....

all else fails 1-800-wal-mart <<<<works EVERY friggin time
A guy who had the brand spaking new CTS caddy when it came out with the v-8 and it took cartridge filters he called that number and complained that we couldn't do his oil change (didn't stock the filter) 1 week later 4 boxes (12 filters each) were in our bay area...hehe :hgrin:

damn, i really didnt know walmart cared about there customers that much. shiet, last time i walked into a walmart, everyone was a minority with attitude that looked sleazy LOL no offense.

but ill give it a try

hehe like i said it varies by stores...I work at the newest one in a 20 mile radius (geesus) and the ones that are around us are in the ghettos pretty much this one is near windermere so we get the rich bitches and such