Yes, if you drive it more enthusiastically than an everyday commuter car you'll pretty much be at a loss without one. If you're using a ceramic coated tubular manifold I'd guess you're going for more than 150bhp with this.

Having fun on roads and using over 4,000rpm for more than 3 minutes or so was seeing my oil temp rise past 260F. With the oil cooler on now, normal driving sees 210-215F, and fast driving sees it at 225-240F.