15w-40 Oil grade, what will happen if i used it

[JDMAlex]

When i had this mechanic fix my oil leak on my old car few years back he sugested i put some 15w40 Oil ....

now i dont know every thing but im shure when i put that in its gonna be a hell of a lot thicker and could slow things down? or kill my engine..


he said it quiets the engine up nicely...


what do you think... i still havent done it because i dont really think its a good idea.

[mrhonda]

Nooooo.....I wouldn't use anything but 5W/30. If you have really high milage you can use 10W/30, but no thicker than that.

[91accord4door]

Nooooo.....I wouldn't use anything but 5W/30. If you have really high milage you can use 10W/30, but no thicker than that.

my civic has 128k miles now, i use 10w30 high mileage gtx...is that alright? seams fine to me. lemme know,

[starchland]

Using a thicker motor oil is nothing more than a temporary solution so that less gets by the rings, much like those additives that also do the same thing. Basically if you know your engine is on its way out, then sure use athicker oil, but if you dont have a problem with your motor dont use it. Why was your motor leaking in the first place?

[JDMAlex]

it was just a Oil temp sensor that was old and it was leaking threw the sensor , and some gaskets in arount the spark plugs because it started to leak there before..

but its not the car im using now .. i was just wondering if thicker oil did some cleaning in the engine or did it fuck it up slowly.

[squig808]

You should use what's recommended, but...
If you live where it's hot all the time, or your running the car hard (racing). 15W40 shouldn't be a problem. If you use a high quality full synthetic 15W40, it's probably ideal if you're "running hot" ie. lots of extended driving, track days, hot weather... I can't see why it would wreck stuff. Probably just decrease mileage, maybe harder starts (especially when it's colder). Bad news if it's cold out (below 10°F or -12°C) or your driving is a lot of short trips.
I'm not aware of any cleaning advantages unless we're talking about not having to clean oil off your driveway , but 15W40 is a poor solution for that. Oil additives will help clean, high quality oils will have this already.

[Bluejayde]

I used a case of 10w40 and some stop leak to seal up my engine until I could rebuild it. HUGE loss in power.

Currently using 5w20 in my KA24, and I like it, but I think I'm gonna go 10w20 for added protection this summer.

[zoomspeed05]

more than 130,000 miles use 20w 50

[mrhonda]

more than 130,000 miles use 20w 50

NOOOO....absolutely not! That is WAY too thick for these engines. Like I said before; 5W/30 is the only viscosity you should be using in these cars....10W/30 at the most.

[accrdpower]

hahhahaahahaha once again have anyone used 20w-50???? if not than shhh. i use 20w-50 during the summer only and been using it for 3 summers. and i must say it is great. NO power loss and no more leaking. now 20w-50 is bad in cold. i use 5w-30 in the winter. i think i have actually had better performance with the 20w-50. u r right about cold and short trips.....the higher viscosity is NOT for alot of short trips or cold weather. other than that whoo hoo 20w-50.

[JDM4DOORLX]

I used to use 20W/50 in my aircooled VW, beacause it always ran hot. I got pissed at the guy at Jiffy Lube who used 10W/30 (I know dumb move) and made him change it back to 5W/30 for free. I changed it myself since then.

[kapone]

for the person who recomended 20w50, i would like for you to take your engine apart and look at the size of your oil jakets and especially the oil chambers that transport it to the cams and the rockers and explaine to me how oil that thick is flowing nicely through those small ass holes, their is a reson why the manufacture recomends a sertain viscosity its because they didnt built your engine to flow suck thick shit... and im not even going to try to explane the oil pump issues with such thick oil ...

[i97supratti]

How does this sound .... I filled in 4 quarts of Castrol 10W-30 yesterday. My car usually burns a quart of oil like every month or so. I plan on adding Mobil 5W-30 for each quart that burns. So i'll have a weird mixture of 10W-30 and 5W-30 as my car burns out oil. Does this sound alrite? What do u guys think of Castrol oil? I know mobil is highly recommended on these forums

[do0dfromcali]

How about 0w-30

[KillerCam282]

So...No power loss, and yet a higher viscosity.

When did the laws of physics get repealed?

I don't know when those laws got repealed. IMO in these engines you are really playing with engine failure with those super thick oils you guys are using. The most you should use on these engines are 10w-30. That 20w-50 will definitelty burn you oil pump which can cause critical engine failure.