coupe

I know this is an old thread, but the question still keeps showing up in internet searches without a current answer for those of us that want to maintain the original spec parts, etc (at 160k miles-I see no reason to change). The original owner's manual recommended GM part number 89021184 for power steering fluid on my 2011 Silverado VortecMax. It was apparently replaced by GM part number 89021185. Both have now been replaced by GM part number 19329450, which also crosses over to AC Delco part number 105074. Both are 16 oz bottles, are mineral oil-based with a special additive, and are currently available anywhere that sells AC Delco parts.