Engine oil Shell or IDEMITSU

So this morning I went n got some Rotella T6 5w40. filled her up and drove it pretty far. The light didnt come back on. I guess all I needed was an oil change? Sounds a lot quieter in idle too, no ticking besides the fuel injectors.

I go back and forth between white jug rotella in the summer and t6 in the winter. It's cheap, and I've never had any issues.

My local AZ sells Mobil 1 10W-40 Racing 4T, Castrol 10W-40 and 20W-50 synthetic bike oil, and the best bargain of the bunch is Shell Rotella 5W-40 Synthetic T6, which is [rated JASO-MA and MA2](http://s7d9.scene7.com/is/content/GenuinePartsCompany/1843126pdf) (although claimed to meet the spec by Shell, it's apparently not officially certified by JASO).

Shell Rotella T. The normal type NOT the synthetic. It's a diesel oil you can use with gasoline engines. It's got all the good stuff you need.

Rotella T6 is very popular for turbo Subarus. It's 5w-40, which has some advantages. It's cheap at $20/gallon.

Speaking of Rotella, Here's a personal observation of mine. My beater Saturn 1.9 has a lifter tick (not fixing it, don't care), so I just put in Rotella T, and it quiets it up a bunch!

ROTELLA T6 - Instantly i noticed a very nice purr from the motor. Its a heavy oil and with stabilizer (in this case thinner than the oil) It warmed up slower, meaning that it was absorbing more heat. No extra start up noise at all. The biggest gain from the Rotella was hot weather stability. It seemed to perform the best when you drove the car hard! Hot weather didnt affect the engines power anymore, and that made me really happy. Turbo lag was increased slightly, and the engine revved slightly slower, but remained perfectly stable. I loved this oil for protection, its really good for hot weather!

I'm running T6 in my car as well It's been great the last few changes, best oil I've used for my 1.8T and I have over 190k on my engine.

Jumpers, disc golf bag, sleeping bag, old winter jacket w/ wool socks, OEM jack w/breaker bar, 4 qt Rotella T6.

You don't need to add any more additives to modern day oils. You said you will be using Mazda 0W-20 oil? This is one of the best 0W-20 oils on the market. It is made by Idemitsu for Mazda. It has very high Viscosity Index of 221. Most 0W-20 oils are around 170. This means it is one of the lightest 0W-20 at start up. This is what you want in the winter.