At 11,000 miles you have problems?

Mine had 13,000 on it in four years. Cars not driven often can be a pain!!! Gas does not "sit' well and can varnish or gum up. I like the injector cleaner idea!

I have never heard of anyone using mid-grade gas in a high compression engine like the XF's. Why not TRY the RIGHT gas and some injector cleaner for a few tankfuls and see how it goes - before spending money on a garage?

Expensive gas could save you money in the long run, Wendyjo!

EDIT: There are some real gearheads here, Wendy. I can't wait to see their answers about midgrade gas. I know my little babe will never "drink from the middle pump"!