like the title says, which weight do you all use??? im having a tiny tiny problem with my car smoking, and i think its cause im using a really light oil.... 10w 30 synthetic.... i was thinkin a little bit heavier, like 15w 40 or something???
20W-50 I like heavier oil for protection,but I've have also been told running heavier oil can hurt performance which I don't know if I believe that or not.
Using a heavy oil does hurt performance and is pretty much useless on a street motor. Heavy oil is good in an engine that is continuosly running at high RPM for a long period of time like Nascar Engines do.
Don't use 15W40 or 20W50. It's pointless. Try sticking with 10W30, 5W30 or 5W50 which is what I am going to try here soon.
so running a slightly heavier oil wont cure my very tiny oil burning problem???the motor only has like 2000 miles on it.... i dont know whats going on. it didnt do this till i fixed every vacum leak on it...
A heavier oil (such as 20w-50) will not do any more damage than a thinner oil (like 10w-30). This is simply a myth prepetuated because most car manafacturers happen to recommend thinner oils in newer vehicles. In fact, those who live in hotter climates should probably use a thicker oil than those in cooler climates. Driving in the summer in 92 degree heat with 95% humidity definitly puts a lot of extra strain on an engine. Persaonally, I've used non-synthetic Castrol 20w-50 for seven years in my Fox and never had a problem.
I use 100% full synthetic amsoil series 2000 synthetic 0W-30 that is right 0W30.It runs 8.35 a quart straight from amsoil but who said the best was cheap.I only need 6 quarts twice a year so it isn't that much when you think how much money in gas we spend to keep the beast alive.1-800-956-5695 is amsoil's orderline if anyone wants it.I wanted to use amsoil forever but could never find it.They have full 100% synthetic 10w30 or 5w30 for 5.85 a quart I think.
on older engines in an era gone now, folks used to run 30 weight on anything with over 70-80K miles (before wide spread use of multi weight oils). same reasoning as those using 20W-50 in their stangs.
i use 20W-50 for 9 months, and 10-40 in the "winter" (winter in Tucson means highs of 60* instead of 110*).
for a mill with some miles on it, the tolerances are not what they used to be; thicker oil should be fine (IMHO) if a less viscous oil is allowing burning, less pressure than is liked, etc.
you really want the thinnest oil that keeps some viscosity when at its hottest. all new cars (most of them) have specified 5W and 10W-30 oils. thinner, as mentioned leads to better economy, which is necessary for various reasons when manufacturers have the vehicles tested.
now i know some new cars have really small clearances and PASSAGES. thicker oil might be ok for worn tolerances, but you have to be conscientious of the passages that the oil must flow through.
i personally like thicker oils. i hate the 10W-30 oils. anyone whom has changed the stuff out of a car when it is hot, knows it is about as viscous as water. my brain does not like to see that. remember, i fight viscosity breakdown and thinning in my climate. i still run 10-30 in some of the newer cars. i will likely continue until they start burning or pressure drops off.
Driftin, i would not want to go with too long of an extended OCI on the 5W-50 you use. the larger than normal difference in the viscosities leads to more shearing. i do run the same stuff in a car of mine, which i start every few months and drive to a car show once a year. nice flow when cold, and theoretically holds up decently in hotter temps.
this is all just my two cents, based on what i know and have read. i could be wrong, but that is one reason to post this; so people can refute it and we all learn. good luck to all.
Right now my Stang has Mobil 1 10W30 in it because that's what the previous owner put in it back in January. I will switch to Mobil 1 15W50 at the next oil change. I'm pretty sure fully synthetic 15W50 will flow at least as well (if not better) at 32F than standard 5W30. And I like having the protection of a thicker oil that will maintain its viscosity better even under hot temps or high loads.
Oil pressure seems to come up just as quickly at cold temps with either thicker or thinner oil, but the thicker oils keep the oil pressure higher when the motor is running. This is most evident at idle. My Fiero has actual PSI indicators on its oil pressure gauge. While running 5W30, at idle, it would drop down below 20psi when hot. With 15W50, the only time it would get down to 30psi was if I'd been running the motor hard on a hot day. Otherwise it would rarely get below 35psi.
when bone stock i used 5w30. then after the rebuild my mechanic said to use 15w40 due to the increased tolerances used, so i did until the break-in period was up. now i run 10w30 100% synthetic.