Engine oil OEM Mazda or AMSOIL

I\u2019ve been using Amsoil Sig Series ever since my first break-in oil change. I used it in my old turbo Cobalt SS that I drove like a jackass when I was younger too. Never had any engine issues and Blackstone analysis shows that up to a 4,500 mile oil change interval is safe for my WRX.

Amsoil always over anyone. I started with AMSOIL in 2004 and after pulling my Hayabusa Engine @ 20k miles to build for a turbo kit, the engine teardown was perfect, the block, pistons and bearings looked entirely new.

Have noticed on several times that when I went from Subaru OEM oil to Amsoil BACK to OEM that it runs much quieter and smoother on Amsoil.

But I run Amsoil signature blend in my vehicles. And I also push 15,000-25,000 miles per change.

I have seen my friends and family use amsoil for 25000kms each change and their cars do 200k- 300k without any engine issues.

I already added to engine oil and transmission. 5mpg improvement avg. already.

Change the oil at a minimum, and do it regularly. Use a quality synthetic high mileage oil and change it again in a couple thousand miles, then change on regular 5k mile intervals.

Switch to Amsoil products and go every 6,000. I honestly would go every 7500 with it if it was me driving that much.

AmsOil 10w30 for turbo engines... haven't had any issues yet. Still consumes it though.

Amsoil's biggest 'benefit' is a longer service life. Their additive pack doesn't break down as quickly, so you can run it longer between oil changes. However, if you're paying twice as much and running it twice as long, it's a wash and you're not gaining anything. When I was selling Amsoil, I had a modified 4 banger and a high mileage 24v that had both been running Rotella for the entire time that I owned them before switching to T6 when it was introduced. I pulled UOA samples every 1k miles, then switched to Amsoil Signature after 5k and did the same thing except I pushed the Cummins to 10k. Zero improvement in fuel dilution, wear markers, or carbon build-up. After seeing there was no real-world benefit, I stopped selling it. I won't market a product I don't believe in, let alone one that I see as an outright scam.