Cadillac XLR

Cadillac XLR specs: the two versions side by side

Names are taken exactly from the catalogue. If you are matching a listing, 4.4 AT is the 449 hp / 331 kW car; 4.6 AT is the 325 hp / 238 kW car. They are not the same engine with a badge change.

Names are taken exactly from the catalogue. If you are matching a listing, 4.4 AT is the 449 hp / 331 kW car; 4.6 AT is the 325 hp / 238 kW car. They are not the same engine with a badge change.

Cadillac XLR engine options: what the numbers actually buy

Both engines are Gasoline, 8 cylinders, V-shaped, 4 valves per cylinder, Front, longitudinal, with Distributed injection (multi-point). That is the common architecture. The split is boost, size, compression, and output.

4.4 AT is the smaller engine by displacement: 4371 cm³ versus 4565 cm³ on 4.6 AT — 194 cm³ less. It still makes 124 hp more (449 versus 325) and 138 Nm more (561 versus 423). Power per litre is 449 ÷ 4.371 ≈ 102.7 hp/L on 4.4 AT against 325 ÷ 4.565 ≈ 71.2 hp/L on 4.6 AT. That gap is the Compressor: 4.4 AT lists Boost as Compressor; 4.6 AT lists Boost as No.

Peak rpm is close but not identical. 4.4 AT reaches 449 hp at 6400 rpm and 561 Nm at 3900 rpm. 4.6 AT reaches 325 hp at 6500 rpm and 423 Nm at 4400 rpm. Torque arrives 500 rpm earlier on the Compressor car.

Compression ratio moves the other way: 9.0 on 4.4 AT, 10.5 on 4.6 AT. Bore × stroke is 91 × 84 on 4.4 AT and 93 × 84 on 4.6 AT — same stroke, 2 mm more bore on the naturally aspirated 4565 cm³ unit.

Gearbox: 4.4 AT is Automatic with 6 gears; 4.6 AT is Automatic with 5 gears. Drive is RWD on both.

If the search is “Cadillac XLR-V engine” in everyday language, the catalogue counterpart with the higher output is 4.4 AT (449 hp, Compressor, 6-speed Automatic). The catalogue does not attach a separate “V” name to the row; the numbers do.

Cadillac XLR hp, torque, and 0–100: performance you can count

0–100 km/h is 5.0 s on 4.4 AT and 5.9 s on 4.6 AT. The Compressor car is 0.9 s quicker. Top speed is 250 km/h on both — the extra 124 hp does not raise the catalogue maximum.

Kerb weight is 1730 kg on 4.4 AT and 1655 kg on 4.6 AT. 4.4 AT is 75 kg heavier. Weight per horsepower is 1730 ÷ 449 ≈ 3.85 kg/hp versus 1655 ÷ 325 ≈ 5.09 kg/hp. The heavier car is still the lighter one per unit of power.

Fuel consumption city, highway, and combined: not measured for 4.4 AT and not measured for 4.6 AT. CO2: not measured on both. Eco class: not measured on both. You cannot pick the “more economical” XLR from this dataset; the tank is 68 L on both, and that is the only shared energy figure.

Cadillac XLR weight, tank, and dimensions that are (and are not) in the data

Searches for Cadillac XLR dimensions, 2004 Cadillac XLR dimensions, 2005 Cadillac XLR dimensions, 2006 Cadillac XLR dimensions, and 2009 Cadillac XLR dimensions cannot be answered with length, width, height, or wheelbase here: those figures are not in the data. What is measured is kerb weight and tank volume, and they do not change by calendar year inside this generation — both versions are dated 2003-01-01 to 2009-12-31.

Suspension is Independent, leaf spring front and rear on both. Brakes are Disc front and Disc rear on both (catalogue label: Disc). Chassis type is not a differentiator.

Cadillac XLR engine reliability and problems: what this catalogue does not measure

Engine problems, engine reliability, engine swap, engine bay, engine cover, and engine for sale are common search phrases. This dataset does not record failure rates, service intervals, or parts. Those topics are not measured. What is measured is configuration: Gasoline, 8, V-shaped, 4 valves per cylinder, Front, longitudinal, Distributed injection (multi-point), plus Compressor versus No.

If you need a reliability verdict, it is not in these rows. Do not treat silence as “no problems.”

Which Cadillac XLR version to choose

There is one generation and two versions. There is no later generation that “fixed” the first. A 2004, 2005, 2006, 2007, or 2008 car in this catalogue is still either 4.6 AT or 4.4 AT.

Choose 4.6 AT (325 hp) if the priority is the lighter kerb (1655 kg), the higher compression (10.5), the larger displacement (4565 cm³), and Boost: No. You give up 124 hp, 138 Nm, one Automatic gear (5 versus 6), and 0.9 s of 0–100 km/h. You keep the same 250 km/h top speed, the same 68 L tank, the same RWD Roadster, and the same Independent, leaf spring suspension. Fuel use is not measured, so you cannot claim it is cheaper to run from these numbers.

Choose 4.4 AT (449 hp) if the priority is output and the 0–100 km/h figure. You get 449 hp at 6400 rpm, 561 Nm at 3900 rpm, Compressor, Automatic with 6 gears, 5.0 s to 100 km/h, and ≈102.7 hp/L. You pay 75 kg of kerb weight (1730 kg) and a lower compression ratio (9.0). You do not get a higher catalogue top speed. You do not get measured fuel figures. Gross weight, ground clearance, and wheels remain not measured, so you cannot score “the bigger car” on size.

Do not choose by year of search (“Cadillac XLR 2026”, “Cadillac XLR specs 2004”, “2008 Cadillac XLR specs”). Production in the data ends 2009-12-31. There is no 2026 generation here. Specs do not fork by 2004 versus 2007 versus 2008 inside these two rows.

Do not choose by price. Sale price, “for sale near me,” and XLR-V price are not in the data.

Arithmetic summary of the extra output on 4.4 AT versus 4.6 AT: +124 hp (+38% on 325), +138 Nm (+33% on 423), −194 cm³ displacement, +75 kg kerb, −0.9 s to 100 km/h, 0 km/h difference at the 250 km/h limit, +1 Automatic gear, Compressor instead of No. That is the whole buying delta the catalogue can support.

If the car must be the one people shorthand as the high-output XLR, match 4.4 AT at 449 hp / 561 Nm / 4371 cm³ / Compressor / Automatic 6. If it must be the naturally aspirated 8-cylinder Roadster, match 4.6 AT at 325 hp / 423 Nm / 4565 cm³ / Boost No / Automatic 5. Both are Cadillac XLR, generation 1, Roadster, RWD, 2003-01-01 to 2009-12-31. The rest of a purchase decision — condition, mileage, price — is outside this dataset.