Who's to say the 5k interval contributed to the 400K mileage and a 10k interval wouldn't have? He just chose not to take it out that far.
400K+ = approx. 50K mi. / yr. With that kind of driving and a manual transmission and diesel, I'm not too surprised at 400K.
As for a spotless engine, who's to say a 7.5k or 10k interval wouldn't have kept it just as clean?
I think a lot of BITOGers give particular oil/OCI combos WAY too much credit when the major contributing factor is actually driving pattern (50k mi year is not typical is anybody's book). We do not see oil related failures these days, or even serious premature wear. You're pretty safe with just about anything out there. I think Rotella T or Delo would have done just fine, too.
400K+ = approx. 50K mi. / yr. With that kind of driving and a manual transmission and diesel, I'm not too surprised at 400K.
As for a spotless engine, who's to say a 7.5k or 10k interval wouldn't have kept it just as clean?
I think a lot of BITOGers give particular oil/OCI combos WAY too much credit when the major contributing factor is actually driving pattern (50k mi year is not typical is anybody's book). We do not see oil related failures these days, or even serious premature wear. You're pretty safe with just about anything out there. I think Rotella T or Delo would have done just fine, too.