nota-eg

Alright, today I went to NAPA and got 5w20 because I read on a thread a few days ago that the 5w20 will give better gas mileage than 5w30 or 10w30.

I understand that the 5w or 10w is the startup flow and that the -20 or -30 is the running flow.

Question:
-Does 20 flow more or less than 30 at operating temperatures?
-What determines how much it flows? (IE: thinning out, molecular change)
-If 20 flows less than 30, then why would it save on gas mileage?

OT Question:
-If you use synthetic and the oil can go 10,000 miles, but you have to change the filter, how do you change the filter w/out having oil drain out?

BTW- My motor is a '95 D16 w/ 220k miles, not worried about breaking it b/c I have a new motor going into the car midway through the summer.

Thanks in advance
Nick

PS- All the previous threads I read just turned into synthetic vs dino oil arguments that just confused me and I couldn't tell fact from fiction. So please, if you don't know what you are talking about, please say so. Or don't say it.

edit: past my 5 post
Thanks a lot for clearing up my 2 main questions


Modified by notabassist31 at 4:55 PM 5/31/2005

jethawk

20 weight will flow a little easier since its thinner then 30 weight at OT....and since the 20 is thinner then the 30.... its create less resistence... therefor giving you a slight increase in power and gas mileage over 30 weight (probably not even noticible) if you have no problems with burning oil... then you'll be fine with the 20 weight... or you could also start burning oil... since it'll be easier to get passed the rings...