JFK78

What is the recommended oil weight for use on a turbo'd honda? Honda recommends 5w-30 for a stock motor, so is something thicker like 10w-30 needed with a turbo? Also, in the latest Turbo mag, the turbo'd 750hp GM cavalier uses Mobile 1 15w-50. Stock the cavalier used 5w-30. Is there a reason for this?

b18bvudoo

why would you wanna go thicker w/ a turbo? i use 5w30.

Total'd GSR

DRAG recommends that you use 20w-50 Mobile1

GruvyTune

that's too thick isn't it??

b18b98

i've always been using 10W-30. Seems fine to me.

ekb18c

20-50 is what i use.

Rob03Pro5

Actually, if you think about it this way:

A turbo spins at 90k to 120k+ rpms and produces A LOT of heat! All this heat cooks up the oil and makes it thinner, also decreasing its lubricating effects. So, it would be preferrable to use a thicker oil that will be harder to break down. Like, if you live in a really hot area, you would use a thicker oil for your car, so it wouldn't thin out.. same idea. DRAG's recommendations should be followed for a long lasting turbo.

BLKMamba

I've been told by a porsche turbo owner to use 15w full synthetic. Of course gas mileage will decrease but was told it's beneficial for the motor and turbo to get the best lubrication. Haven't tried it but will try it on my next oil change.

RGAZ

There is no way I could go 20W-50 in Wisconsin, The frickin oil would be like sludge. I use Mobil1 5W30. The 5 helps start-up in cooler weather and the 30 is plenty thick when warm. I'd only use the thicker oil if you have a restriced line to the turbo or a poor oil return line.

The trade-off for saving your turbo a little heat and saving your engine is what I consider most important.

You make the call: rebuild turbo or rebuild engine?

Randy

VTC_CiViC

10W-30 for winter, or what we call winter here in Miami anyways.. then 15W-50 in the summer

brcivic411

i use 10w-30

austrian type-R

I use 10W60 Castrol Formula 1

4dGSR at work

winter 10w 30
summer 15w 50

20 50 is too thick IMO

dustin

I use 10w-30 mobil 1 full synthetic all year.

Flamenco-T

same here

JFK78

I've always used Mobile 1 5w-30 syn. Mainly because it is thin (more hp) and a proven brand. However, my car consumes 1 qt every 3000 miles or so, and at idle and at 3000 rpm fully warmed up, my oil pressure is 10-15 psi lower than it should be according to the helms manual. It kind of scares me, even though I've had 30,000 trouble-free miles with it.

I recently tried Castrol Syntec 5w-50 and my oil pressure is now where it's supposed to be. It also didn't consume any oil after 3000 miles. But its thicker and thus probably makes less hp.

A side note- when I dyno'ed my car with the Mobile 1, above 5000 rpm there was a lot of smoke pouring out of my valve cover breather filter. Could this have been due to the oil being so thin?

Also, since the car is obviously burning some of the Mobile 1, could the small amount of oil getting into the combustion chamber at high rpm be causing or making detonation more likely? For this reason only, I would be willing to go to a slightly thicker oil.

One more ? - no matter if its a 0w, 5w, or 10w, if it is a -30 weight doesn't that mean they all would be the same once up to temp? And that they would just be different thicknesses when cold only?

RGAZ

The first number is the cold temp thickness (smaller is thinner) so the second number is all that really matters unless you have really cold temps (below 0F).

The smoke out the valve cover breather is because you have excessive blowby and the crank is getting overpressurized. Under boost the PCV system does not work exactly as it should and the pressure can come out the breather. its possible the PCV valve is bad and the boost is pressurizing the crankcase. That would be very bad for your seals/gaskets.

Randy

quikrpm'z

Jfk,

what diff oil pressures were u seeing at idle and above 3k.

Giuseppe

do u have these oil grades reversed..???

i would think u would want the 10w30 in the summer
and the lighter 5w30 in the winter for cold startups..

JFK78

The manual says it should be 50 psi at 3000 rpm and I'm not quite sure on the idle pressure, I think it was like 20 psi.

With the Mobile 1 5w-30 I would get like 40 psi at 3000 rpm and sometimes even less (like 35 psi) if I was running high speed on the freeway for a long time. At idle it barely registers on the gauge, like maybe 10-12 psi. I was beginning to think that my crank and/or rod bearings were worn because of the low pressure, but when I removed the oil pan for the turbo install everything looked perfect.

When I use the Syntec 5w-50, my 3000 rpm pressure is 50 psi, and maybe 45 psi on extended freeway trips. At idle its about 15-20 psi, but I think the oil pressure gauge might be a little inaccurate at low pressure since its a short sweep electric auto meter gauge.

TurboSedan

That is my plan..........here in MI it gets below 0F in the winter (except this year), and sometimes over 100F in the summer.

LSej1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HT Contributor &raquo;</TD></TR><TR><TD CLASS="quote">I use 10w-30 mobil 1 full synthetic all year.</TD></TR></TABLE>
x2 for the win

tekturbo

I have to agree with the people saying to use the 10w30 or thicker,because I use to use 5w30 and I use to smoke like hell out of my exhaust after ripping. When I switch to 10w30 I dont smoke anymore, so I have to agree not to go too thin on the oil at all with a turbo motor maybe with an N/A moptor it would be wise to go with those thinner jdm oils and such but with my experience and a couple of others nothing under 10w30.

oneludesol

multiweight oil is in every way inferior to single weight oil. be smart and run the oil you need for your climate. It is summer now, this discussion should be only about 30, 40, 50, and 60 weights, and it is my experience that 50 and 60 is too thick. when i went from 30wt to 50wt my turbo ended up spooling up almost 1000rpm late no lie, needless to say im back on 30wt and afraid to try 40wt because im really **** about any increase in lag due to oil for crying out loud!

Mfoehrkolb

I was always under the assumption that the oil of choice begins on how your motor is built. Depending on the clearance you give on the rod bearings and main bearings. The more clearance the thicker the oil, minimal clearance is thinner oil. Always keeping in mind, the current weather. Maybe im wrong though.