How much better can titanium be? Titleist went to Mars to find out. These drivers use a titanium alloy (ATI 425) in the face originally developed for NASA’s Phoenix Mars Lander. In other words, it’s light, flexible, strong and resilient – just the right material to smash a golf ball. This alloy’s strength-to-weight ratio allowed the designers to pursue a more aggressive variable-thickness face to get more distance. Ball speed is great, of course, but using a lighter material improves the forgiveness in these heads, too: The deeper and lower centre of gravity offers increased stability on strikes towards the heel and toe and low and high. The result is consistent spin and launch conditions for a more efficient ball flight – even on less-efficient impacts. Titleist made aerodynamic shaping a priority for both heads, but each features a different look and focus. The TSi2’s larger shape speaks to its overall forgiveness and higher launch. The more compact, flatter-launching TSi3 uses its extra mass in an eight-gram rear perimeter weight chip that fits into five settings.

LOFTS 8, 9, 10, 11 (tsi2, tsi3); adjustable

Reviewer profile

“A classic pear shape that’s still stable at impact. It has the same sound all over the face. Instills confidence at address to swing hard and watch it go straight.”

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