any bad side effects on using 0-30

A 0w-30 oil has a 0 weight base stock so that it will flow well in the winter when it is very cold. If you live in a place where it spends long periods below 0 you could benifit from this oil. The 30 means that as it warms up to operating temperature the oil will flow like a 30 weight oil does at operating temperature providing more protection than a 0 weight oil at operating temperature could. Since you live in California I see no benifit in using the 0 weight.

I see a benefit in the first several seconds of engine start. The oil will be aproximately 70* or less from overnight cooling. The viscosity will be relatively high until the engine warms up. The 0W viscosity will flow more easily on initial engine start and for the several minutes there after until the engine begins to warm up to operating temperature.

Most of the wear damage to engines is in the initial engine start period, something like 70%. An 0W oil will have better viscosity than a 5W or 10W oil and therefore less initial engine start damage.

Bob Weis

if it matters i got amsoil 0-30 serries 2000. it supposidly racing oil that last up to a year. look it up if you guys are curious about good oil.

Benefits of oil flow when cold but not artic?

Race oils tend to have additives taken out to deal with race situations rather than road use, so race oils may not be best option unless also used as a track car.

Synthetics naturally flow at cold temps so the base oil would not be 0wt. Redline Straight wt race oils can also be classed as multigrade.

Hi tuong,

Yes, using a 0W-30 will be fine. I'm not sure if Amsoil's S2K oils are actually considered "racing" oils, but I believe they are some of the best products Amsoil produces. The explanation given to you about xW-xx labeling is off with regards to the "velocity" comment. First, keep in mind that oil viscosity is measured at 212°F (100°C). Oil companies also often list an oil's viscosity at 104°F (40°C) for informational purposes, but your engine usually spends only a fraction of time at that temperature (SW US desert dwellers excepted).

What do the different numbers mean? Let's take 10W-30 as an example. The rating only means that the oil flows like a frozen 10 wt when it's really cold (minus 20°F) instead of a frozen 30 wt (which would be thicker than you'd like at minus 20°F), & then behaves like any 30 wt would when it's hot (210°F & hotter). The cold rating (xW- end of things) should be viewed as being completely separate from the hot rating (the 30, 40 or 50 wt part) & is simply a labeling convenience to help you pick an effective oil for your start-up climate. The hot rating is where you'll get all your operating temperature protection, & should be chosen based on the engine's design & protection needs. Separate the two numbers in your mind!

Done that? OK, good! Now consider this: ANY motor oil will be thicker below 104°F (40°C) than ANY OTHER motor oil will be above 212°F (100°C)!! What does THAT really mean? It means the "thinnest" 0W-20 will be thicker for all of your cold starts than the "thickest" 20W-50 will be once it's flowing & the engine's warmed up to operating temperature!

As RWeis said, the 0W-xx oil will get pumped thru your engine to protect it quicker than a comparable 5W-xx or 10W-xx oil. So even if it's relatively warm where you live, you can definitely benefit from the extra flow-ability & protection of a 0W-xx synthetic. MGBV8 mentioned that synthetics naturally cold flow better, which is true, but the hot end also benefits, as synthetics tend to thin less when they go above the viscosity-rating 212°F. It really is a win-win situation when switching over to "true" syn oils like Amsoil & Mobil 1.

thank you