WTI is the underlying commodity for both the ICE contract of crude oil and also the NYMEX contract.

Industry commodity calendars show that, for purposes of Last Trading Day, etc., they are listed as "ICE WTI Crude" and "NY Crude Lt."  However, if you go to our Commodity Quotes section on Energy, you will find that contracts for both closed at exactly the same price.  For example, the November 19 close for January deliveries of both ICE and NYMEX was $89.28, that for February was $89.80, and etc.  We have always used WTI for our cash price.

However, Brent Crude actually trades at a significant premium over WTI.  For example, whereas January delivery ICE and NYMEX closed at $89.28 on November 19, the ICE Brent Crude for January delivery closed at $111.70 --- a premium of $22.42.

Read more here: http://www.cmegroup.com/trading/energy/light-sweet-crude-oil.html