OCI on Shell Ultra

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Jan 23, 2014
Seeing as this is the highest cleaning oil, does this mean that OCI should be shorter than other oils? Car is 6G74 3.5L Mitsubishi Diamante, 120K miles
I would imagine that would depend on how dirty the engine is. If the engine is clean I would do a regular OCI but I'd shorten it (or maybe change the filter) if the engine appears to have sludge. I guess this oil is similar to Pennzoil's 'Ultra' here in America. Does it mention 'GTL' on the label?
If the engine is clean, there is nothing to contaminate the oil and regular oci is fine. If engine is dirty, shorter oci is preferred.
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Yes I think this is identical to the Pennzoil Ultra. I've had the rocker covers off and the engine has no sludge, but everything has varnish on it (this is what I am hoping to remove).
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