Rotella T Synthetic 5W-40 is a Full 100% synthetic motor oil (dark blue bottle)
Check the specs of all Shell Rotella Oils at
www.rotella.com
Even when using synthetics... I think frequent oil changes has kept all my vehicles going for a long long time. Forget 10K to 15K on synthetic oil....thats just asking for a premature rebuild.
__________________
FRED
Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K