leokcm

Hey guys

I need you guys opinion about engine oil.

As you know, engine oil is most important factor to the car.

I want to change my baby's engine oil which one is good for high RPM user.

I want to get you guys precious information.

Thanks your time and drive safley!!

iSuxeL

iTrader: (21)

Royal Purple 5w30, though I'm thinking of switching to 0w30 cause I'm in FL

XhyDra

iTrader: (8)

Royal Purple 5W-20
You can find it at Pepboys or most auto parts.

kuuqi

i've heard royal purple gives you a decent (though slight) boost in HP but also at the same time it wears down a lot quicker when compared to other oils.

just a quick run down of oil basics if you don't already know, the first number if the viscosity of the oil on cold startups and the second number is the viscosity after warmup. a higher viscosity oil can manage high RPM's better since it's thicker and can lubricate better under heavy load. lexus recommends 5w20 as of now for the IS which is great all around as the 5w works fine in slightly below freezing temperatures and the 20 is thin enough to get better gas mileage on the engines as well as giving sufficient lubrication under load.

if the difference between the cold startup rating and the warmed up rating is too great, there are a LOT of additives in it that causes the oil to break down faster which isn't something you want. under daily use, i recommend 5w20. if there's no cold winters in your area and you run the car under heavy loads, 10w30 will work better since the higher viscosity will work better under high RPMs. i remember reading that the IS-F recommends a viscosity rating as high as 40-50 because of the heavy load needed under track driving. i wouldn't recommend over 30 since your car isn't really going to run as hard as the IS-F.

i also recommend you changing your oil before and after track runs. heavy track load wears down the oil faster and the heavier weight of the oil isn't great for your gas mileage.

so under daily conditions, 5w20 or 5w30 and under track conditions, run a 5w30 or 10w30.

if you DO have cold winters below freezing, 5w20 or 5w30 only (or even 0w20 if it's THAT cold). also once you start with one brand, stick with that brand.

brand wise, amsoil and mobil 1 make great oils, where mobil 1 is much more readily available in stores. amsoil is difficult to find. so considering all these factors, you'll have to think of what you will do with the car and under what conditions to maximize protection and the longevity of your vehicle. i personally run 5w30 during the winters (thinking of switching to 5w20 though) and 10w30 in the summers since i go up onto the hills more often.

IS35O

Been using Amsoil 0w20 since 5k miles, almost at 30k and all is well.