Performance Probe-The Ford Probe Forums

Posted: **Mon May 14, 2018 6:40 pm**

What oil are you using?

I use castol 10w40 half syn, been using the same oil forever.

Posted: **Thu May 17, 2018 9:09 am**

Pends on time of year, hot months I'm with ya on the 10w40, back down to 10w30 as winters can be cold here. Straight up conventional Valvoline.

Posted: **Sun Aug 30, 2026 10:48 pm**

I've been using Delo 15W-40 in my 1991 GT for the past 15 years.

Posted: **Wed Sep 02, 2026 4:52 am**

techguru wrote: ↑
Sun Aug 30, 2026 10:48 pm
I've been using Delo 15W-40 in my 1991 GT for the past 15 years.

yep good stuff, i run rotella 5w40 in are 2nd gen gt's

Oil