[naz]

NOS2Go4Me,Jun 6 2007, 01:04 AM Wrote:Naz - thanks for the heads-up man! I like your setup for your gauges.

Also, what's the penalty about running 15W40 vs what we have now (5W20)? Wouldn't the haavier stuff not flow correctly through the engine, starving it of lubrication when it's needed the most (high RPMs / boost)?

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that isn't my car.. my setup is similar though.. i have that omori boost gauge on the right side of the column (with yellow needle) and a factory dash gauge pod in place of the stock clock that has EGT, oil pressure and a clock. i'll take a pic later

in my owner's manual and factory service manual 5W30 is the 'preferred' oil viscosity (general consensus is that this is for US EPA fuel economy standards.. in other parts of the world the factory oil is apparently thicker) but the also manuals suggest that if the vehicle is driven hard (ie desert conditions, towing) (i infer that bombing through the mountains with your buddies or going on a track day counts as hard driving) you could go all the way up to 20W50

from what i've read lighter oil (5w30) is better for fuel economy, but when the oil heats up (ie hard driving) it shears down.. so like.. a 20 weight, which is apparently too light and no good.. a thicker oil such as 15W40 (esp a 'heavy duty' one designed for stressful applications) is supposedly able to not shear and keep lubricating even when its really hot... so a heavier oil is actually better for high rpm/boost hard driving...

i think a good way bring tech to this issue is to get the oil analyzed and check for wear metals and see how the additive package is holding up. for my car and bike people have used shell rotella T 15W40 dino oil with 3000mi change intervals and gotten good oil analyses back, so that is good enough proof for me (and it doesn't hurt the stuff costs a fraction of full synth)