2010 Cadillac SRX SUV

General Motors’ Cadillac luxury brand has dumped its conservatively styled, seven-passenger SRX crossover SUV and replaced it with a new version of the SRX designed to be like the Lexus RX 350 SUV.

The RX dominates luxury, midsize crossover SUVs, selling three times as many through August this year as its nearest rival among upscale five-passenger crossovers, the Lincoln MKX: 48,176 vs. 14,874, according to industry sales tracker Autodata. Caddy sold just 5,904 of the old SRX in that period.

The old SRX also is on Consumer Reports’ “worst of the worst” list for perennial reliability problems, which hurts.

The remade 2010 SRX comes in two versions, differentiated only by the drivetrain. The one that Caddy says nine of 10 buyers will choose has a 3-liter V-6, GM six-speed Hydra-Matic automatic transmission and front-wheel drive (FWD) or all-wheel drive (AWD).

The high-end version, due in 30 to 60 days, comes only with AWD and lots of accessories. Its strong selling point: a 2.8-liter, turbocharged V-6 and Aisin Warner six-speed automatic. This powertrain also is used by Saab (once owned by GM) and Opel (about to be sold by GM). It boasts 300 horsepower and 295 pounds-feet of torque vs. the 3-liter’s 265 hp and 223 lbs.-ft.

A preproduction 2.8/Aisin test car delivered crisp shifts, up or down, without jarring or waiting. That made it immeasurably more pleasant to drive than the regular-production 3-liter test vehicle with its stumble-shift, wait-a-minute operation.

Caddy’s 2.8 turbo V-6 rolled out sweet, unending force. It’s tuned to deliver the turbo’s full measure of power-increasing boost at just 2,000 rpm and hold it through 5,000 rpm. No lag, no sag. Yum.

The 2.8’s additional hustle was a bonus, but you needn’t want the extra power to prefer the 2.8. You only need to favor a drivetrain that works right.

Exact pricing isn’t set, but expect the 2.8 turbo model to start at about $49,000, about $3,000 more than a similarly equipped 3-liter vehicle, says Bob Reuter, global chief engineer for GM’s compact crossover SUVs, including the Chevrolet Equinox, last week’s Test Drive.

GM considered basing Equinox and SRX on the same platform but chose a separate chassis for SRX because it wasn’t certain GM could make a Caddy with Chevy underpinnings, Reuter says.