My friend is looking to buy a GTO in the next few weeks and I can't seem to find any info on the differences between the 5.7 and the 6.0 besides HP. Anyone wanna help me out here?

 

hood, rear bumper, brakes, wheel options, color options, font on the speedometer are different between 04-05,06, slightly better metalurgy in the 05-06 drivetrain......electronic throttle body on the 05-06 vs throttle cable on the 04

If you find a low mileage 04 the 05-06 upgrades can be accomplished very simply and the 04 ls1 doesn't have the oil consumption issues that the 05-06 LS2's are notorious for...

 

There's definitely quite a few. Besides the ones mentioned above, there are also a few differences that are less of a decision-making preference, such as the location of the coolant tank on the '04. It's a visible, clear reservoir placed by the driver's side strut tower, where the ECU is mounted on the '05/'06 models. All '05 model years, and most '06 model years have the connection for the JHP center pod cluster for the voltage and oil pressure gauge. The '06 has lighted steering wheel buttons (for audio control), as well as a power door lock button... which the '04 nor '05 have.

I think that the '06 models offered a smoker's package (ashtray and cigarette lighter) beneath the stereo. 18" wheels were an option for the '05/'06 years, but it's a reasonably rare package to come across. Along with the split rear bumper on the '05/'06 is obviously split rear dual exhaust, where the '04 has a single-exit dual exhaust on the driver's side. As summerwolf mentioned about the drivetrain, I believe the only real difference was that the automatic '05/'06 GTO's are equipped with a 4L65E transmission, which is supposed to be a touch more stout (for lack of correct words) than the 4L60E in the '04. The Tremec M6 transmission did not change between any of the 3 years if I'm not mistaken, but I believe the LS2's may have a slightly larger clutch assembly.

To clarify on the above post-- the hood w/scoops was only available on the LS2 GTO, the LS2 has slightly larger brakes (I believe the fronts are only bigger, not front AND rear, but I could be wrong).

The only real downside to the '05/'06 LS2 GTO's is the strut rub. If it hasn't already been an issue and been taken care of, you'll likely need to replace your front strut mounts on the LS2 GTO before your alignment falls out of whack. The strut mounts collapse very early on the LS2 GTO's, causing a camber issue on the front tires where they come in contact with the struts. It's believed that something was done differently in the transporting of the LS2 GTO's from overseas to the U.S., which caused these mounts to collapse so soon. It's a relatively inexpensive fix if you do it yourself, and you won't have to worry about the problem again once you fix it.

There are a few other extremely minute changes, but I believe that covers the more obvious differences between the years. Feel free to add to list if I'm leaving anything else out guys, but that should get you started!

 

Wheel options are the same for all years as well as hood with scoops, the wheel, scooped hood and sport appearance package options were added late in 04 or early 05 to move left-over or slow selling 04's.
04's have all leather seats and arm rest door panels, red tail lights, flat hood, 5.7, cable tb, drivers side exit true dual exhaust, trans control module is separate from pcm and you can enable "Lean Cruise" to get higher mpg.
05's have 6.0, scooped hood, split dual exhaust, leather where you touch until a certain build date, drive by wire tb, red tail lights, bigger brakes front and rear, no lean cruise, and TCM integrated into pcm.
06's same as 05's except euro style tail lights, lighted steering wheel controls and the power seats are supposed to move faster.

 

the 04 5.7 is the fastest.thats all you need to know..lol

 

how so???

 

cause almost all the fastest gto's are 04's.

 

That is pretty true. It seems that everyone who wanted one with plans to make go seriously fast got one when they first came out in '04. Rather than upgrading to the '05/'06 with the 50 extra horsepower potential, then modifying that, they actually stuck with their '04 and sunk all their money into it.

Plus for such a short time after production of these cars the length of time that one has owned an '04 has given them a 1-year head-start on mods. So where the majority of the '04 guys were last year, the '05 fellas should be this year. So we should be seeing a few new LS2 Goats running 9-second 1/4 mile ET's if that theory holds true.

I started off with a 2004 M6, but before spending several thousands of dollars in bolt-ons just to put out similar power as the new 2005's that came out shortly after kind of discouraged me. I knew I wanted a faster car, and I also liked the idea of bigger brakes and split rear exhaust (my '04 already had an '05 hood on it that I bought with an SAP kit), so the potential of an additional 50 horsepower in stock form just sold me on the LS2 GTO. I sold my '04, and picked up a Maggie'd '05 A4. I'll never look back at the '04/LS1 GTO.

The euro-style tail-lights on the '06 is a great one that I failed to mention. I have them on my '05, and if you like them but can't get your hands on a 2006 then if you can find the '06 tail-lights somewhere you can just swap them out for your '05 ones. It's a simple change-over. Changing over the rear bumper, rear exhaust, hood, and/or brakes from an '05/'06 to an '04 is just not worth the price you'll save in buying a 2004 in my opinion though. If the goodies of the '05/'06 interest you, just spend the extra money on one of those model years and get it over with. That's my advice

 

Dude, to do the rear bumper, hood, brakes etc is less then 1500 bucks if you're smart and search for deals/ then get the stuff repainted. The only thing about the 05-06 that would be worth the extra coin is the engine...and you can put a catback and a CAI on an 04 and have more power to the wheels then an 05-06....

For me personally....I wanted the car from the add on TV....I liked the true duals exiting out the left side...I liked the sleek look. I bought my car in July 0f 05 and I could have easily bought an 05 with the no interest loan....the useless hood scoops and grand prix split bumper just looked goofy to me and on the test drive my particular 04 felt just as strong as the LS2 car....taking it to the track proved that with a horrible 2.21 60 ft and a 13.6 @ 104 bone stock and with me owning the car for about 2 weeks before driving it. With a CAI and a catback and tune she went 13.2 @ 109 with a 2.31 60 ft.....04's run plenty strong IMO and the 05-06 brake upgrade was 150 bucks for the calipers and rotors, 75 bucks for the SS lines, and 12X for the hawk pads....I have chosen not to put on the scooped hood and I would never get rid of my 04's rear bumper....the perfect sleek car I always wanted.

 

The thing you forgot to mention is that the LS1 was a proven engine with a lot of aftermarket parts available for it in 04. When the 05/LS2 can out these guys had to wait for over a year in some cases for even the simplest upgrade. There are still things that, like the Ingalls stiffy that they still can't get. Aftermarket manufacturers jumped on the GTO bandwagon the first year because they like Pontiac expected big sales. When that didn't pan out, not as many we as eager to dump money into designing parts for the LS2 model years.

So yes the 04s rule the top of the ET lists.

 

Don't forget, you could only get the fastest of the fast "Cosmos Purple Metallic" in 04'.
LOL

 

can throttle by wire be put on an '04

 

CPM will cause me to get an 04 one day, I just love that color.

 

why would you ever want to do that? Cable driven throttle body dumdumdum...another reason I wanted an 04 over the 05-06

 

because throttle by wire is awesome you have to understand i am not bolting parts on a gto like you i have to custom fab parts to fit a gto in a 56 truck so throttl by wire we be cool

 

The 04's have lean cruise, the 05-06's don't. This is an option in the ECM that has to be configured with HP tuners. Some guys over on the other board have seen over 30 mpg with this enabled.

 

it is awesome but with my mods and 3.91 gears i "only" get 26 MPG. still pretty damn good for a pretty quick car...

 

The difference is .3