It's "use," goddammit, if you're writing -- or speaking -- everyday, ordinary-person English. "Utilize" says in three syllables what you could say in one and makes you sound pretentious. Using it more than once in the same sentence makes me want to pull out your tongue and twist it all the way around your neck, utilizing the offending organ to strangle you.
Here's what Grammar Girl says:
Bonnie says that as a copy editor she often reads fluffed up marketing material full of big words that try to make the writer sound important or knowledgeable. She usually just changes them to normal, unimpressive words that get the point across without much fuss. One of these words she changes often is “utilize,” as in the pretentious-sounding sentence “If you utilize this brand of printer, you will go far.” A sentence like that sounds fluffy and overly important, and it gives readers the impression that you’re trying too hard. Most of the time you can avoid the verb “utilize”; “use” works just fine.You would think scientists would at least think to bring up the particular science usage. Or maybe just concede this one to the collective yet minority wisdom of their own comms, public affairs, and humanities people? But no. The loudest and lamest excuse I've heard to date? Apparently, "I would rather be utilized than used" is as good a reason as any to overuse "utilize."
So if you’re in marketing or PR, you can just use “use”; it’s probably not a good idea to utilize “utilize.” In a similar vein, please avoid the word “utilization.” It does your sentence no good. Surprisingly, “utilize,” a 19th-century loanword from French, does have very specific and valid uses, mostly in the scientific world. The word “utilize” often appears “in contexts in which a strategy is put to practical advantage or a chemical or nutrient is being taken up and used effectively.” For example, according to the American Heritage Guide to Contemporary Usage and Style, you might hear “utilize” properly used in a sentence such as “If a diet contains too much phosphorus, calcium is not utilized efficiently.”
So if you're a science writer, you might find yourself using the word “utilize.” If you’re just a regular person writing a regular sentence, you should probably just stick with the word “use.”
Granted, we have democracy around here, but so much for evidence-based decision making. And the active voice.