ya you get bulk oil at your cost..=cheaper for you..but for us joes it isnt cheaper..if your cars was subposed to have synh oil in it..ran on synth from new you better stay with it ...and if your car was on normal oil like 5/30 or 10/30 you cant switch it over to synth oil.and vise verse.friend mom just got balled out by a shop..her car had normal oil in it.....she got the car off of her son..couldnt aford the payments on it..

 

It's still 5W20 though; it's just more often than not, not an "energy conserving" oil. For example, Valvoline Conventional 5W20 is a tad less viscous than Valvoline MaxLife High Mileage 5W20. However, 10W30 Conventional is still much more viscous than the HM 5W20. It's still relative to the weight of the oil. As you say, it is but it isn't. I get where you are going with it. The way you worded it originally threw me off.

Not true one bit. I've done both those things, on the same car once even, and never, ever had an issue. There are potential caveats to switching back (and possible forth), but you can do it for sure.

 

actually no. you "joes" get that for the base oil price. we dont start at conventional at our place. actually if you want bottled conventional like castrol valvoline and penzoil. its actually more. and you can run whatever grade of the weight prefered for your vehicle. tho I agree if it requires a full synth oil run it. But I see turboed volkswagons and what not that are supposed to run a full synth run a non synth. runs fine. you can switch between each grade for a car that doesnt call for it. like synthetic in a car that doesnt recommend synthetic. and ect. thats a urban myth.

 

Im sorry I said it wrong. He thinks they are all a 10/30. I KNOW that they are all different weights. i have issues explaining at times haha.

 

So you think,I think there all 10/30?? ..So how many years you worked on cars??..if my car was new I'll be running the 5/30 stuff until it hit the 100000 mark then switch over to 10/30..the reason why they run 5/30 on new cars because there very tight tolerance ...but after 100000 your tight tolerance is no more....thats why I run 10/30 on high miles engines..takes up the tolarance..but if you still want to run the 5/30 they it best to start adding lukas engine oil additive in it..My wife first gen neon we got with 97000 and now with 185000 on it with 175 psi compression..alot of mechanics id talked too said the samething switching to 10/30 on high miles cars..

 

First: what weight are you switching to at 200,000 miles?
Second: why would oil weight affect a compression test? A heavier oil isn't going to fix anything that would cause a low compression reading.

 

Long enough to know what oil goes into cars. ive been doing oil changes on cars for this shop for about 10 yrs now

365 days in a yr minus my days off (fridays, sundays, and the occasional holiday) times 40 to 60 cars a day. pretty sure i know what im doing.

and I am curious to the answers to darthroush's questions. enlighten us please