habitat

Depends on where you live and its temperature. Also, some recommend on higher mileage cars to use an oil with higher viscosity. If your oil show gives you 10w30 with no explanation, maybe you should ask them to read the cap?

mitsuguy

iTrader: (2)

many shops only carry 10W30 in bulk oil and shy away from using canned oil due to its higher expense...

10W-30 is by far the most common oil weight out there...

good shops give you the option, or, should just install the correct weight oil irregardless... our guys are trained to look at the oil cap, tech manuals, and if a question arises, ask the customer... (I try to get my sales guys to do the asking up front, but it gets bypassed sometimes)

fonzo

I run royal purple syn in all my cars never had a problem

pnyboy27

ive been running synthetic on my cars for a long time and have witnessed no problems on mine..i use castrol syntec and k&n oil filter..but i agree with what the others were saying..its probably just cleaning out the excess gunk from the conventional. i would recommend cleaning out your engine with seafoam so it cleans out your engine real well..im planning on doing that sometime soon

SCV8

I tried the longer lasting (15K,advertised) Mobil1 in my old corolla and it worked well, much cleaner oils after over 10K.
I use it now in the SC400, with a propietary, anti wear (probably boron) additive.

Blizzy

iTrader: (-1)

I recently went with synthetic...the 15k mile extended life stuff from Mobil1. I heard it was most prone to leaks, but I have had no loss of oil whatsoever on my 70k mile engine.

I got a 4qt of the 5w30 and a 1qt of the 10w30 to top off the last ~0.75qt of the oil change as I was not about to buy another big jug of the 5w to just sit ambiently in the garage (and that was my only option given the selection at the local Walmart).

I intend to change the oil after 7-8k miles. I will pay the few extra bucks for a little piece of mind considering I will be pushing my V8 hard in a matter of months.

jdmtruong

Conventional for me. I like Castrol.

ridox

ENEOS Full Sythetic Motor Oil 5W40 eneos.us
AMSOIL Ea Oil Filter amsoil.com