I say stick to your current 3-4K schedule. Conventional oil formulations have not radically changed and even with a  synthetic oil you would not want all that dirty oil circulating through your engine for so many miles.
 
-Mark

> On May 15, 2024, at 8:38 AM, Dan N <dn92610@gmail.com> wrote:
> 
> Hi All...
> 
> For a 2.1 WBX... 30+ years ago recommended oil change interval was 3K to 4K
> miles. Since oil quality/composition evolved, is it safe to do oil changes
> at 8K to 10K miles? This is using Conventional Oil (not Synthetic).
> 
> Thank you..
> 
> dan