You would think that, and certainly it is logical. But...! My Aero had a little sludge, and it surprised me. After a short motor was installed, dealer service before I got it, and only 45,000km old at the time. I serviced it and always used the best fully synth oil I could find. Lots of forum action on good brands and value from me on that topic. I did the PCV update kit, changed oil every 10,000km. Yes, I dropped it to get peace of mind, and was glad I did. Messy and time consuming, and was looking for future proofing. That engine lives on in another car now. I miss that car more than i might admit. Every Day.