Engine oil RED LINE or IDEMITSU

Redline is great, used it for years in a track car.

My STI also used it for a while (0w40), but then switched to Rotella.

Redline user have been since I picked up my 04 WRX wagon two years ago. Auto crossed and rally crossed. Works great have had zero issues, also at 170,000 miles on the original engine and still running strong.

I use Redline, similar quality and price to Amsoil, without the MLM BS.

In my experience of trying many different oils, what I think are the best, as far as the engine running cool and smooth shifting are: 1. Redline 15w50

Idemitsu 05-W30 from Unioil kasi I cant find Castrol for my Mazda

Red Line Racing Two Stroke is the best oil I've run. It leaves a good film and smells the nicest.

Idemitsu is responsible for the oil that powered the Mazda 787b; they know the rotary like no other. I exclusively use their synthetic 20w50 and premix.

Regarding brands, if you want to stick with factory oil without dealer price, Idemitsu is the brand to get. I emailed Mazda corporate and they said Idemitsu is the OEM for their oil.

I just put Redline 5w-30 into my 2011 STI at the last oil change. We'll see how it goes.

So when i changed the car to 10w40 redline I noticed that the car began to knock around 3-4k which it didn't do before and now it seems to slowly get worse.