rkhodges21

So I am really wanting a V8 sedan for my next car. My 03 Bonneville has been an awesome car considering the abuse I've dished out on it, but I am really ready to get something newer and V8. I want to keep a sedan because I have 2 kids both still in car seats. 95% of the time a 2 door wouldn't be a problem, but I really want to have a sedan just in case.


So, I want you guys opinion, if you had to do it all over again, would you go with the LS4, or would you rather have the G8 GT?


I am trying to look at the pros and cons of each here.


LS4

Pros: less expensive purchase price and FWD is better in snow (I live in TN, so we don't get much of this, but when we do, FWD is very helpful)


Cons: Fewer aftermarket parts available, weak 4t65, engine configuration is harder to work on.


G8 GT


Pros: 6.0, RWD is more fun for street/ strip, more mods available.


Cons: More expensive, not as good in the snow.




What do you guys think? Am I leaving something off my list here?

spawne32

iTrader: (2)

G8 GT by a long shot. LS4 cars are nice (particularly the GXP) but they cant hold a candle to a G8 GT in the end run. The trans is better on the G8, the engine is better, and overall the car is just better and will last longer. If you bought an LS4 car because of the price being cheaper, expect to spend a couple thousand more in a trans if not immediately after purchase, or sometime down the road in the next few years.

spawne32

iTrader: (2)

plus they look better lol

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rottonj

iTrader: (4)

I would take the G8 also, fuel economy is worse for sure and no HUD I believe(its my favorite thing about the car). I drive my car every winter, its not great but manages. There are snow tires for everything out there for those who want to drop the extra cash, I don't . The G8 is still a ton of money right now, by the time I could afford one they will all be beat to death.

superglide9375

traitors

rkhodges21

Honestly, I'm not seeing prices that I would call a ton of money unless we're talking the G8 GXP. Not many of them around, so they bring really good prices, but the GTs are around $14-18k depending on mileage, with most being near the 100k mark. The GP GXPs and Impala SS are around $10-12k but most have over 125k miles on them. Blue book says they should be around $8k though. Most people post them for sale as "rare cars". That's just around my area though. Could be way different everywhere else.

rottonj

iTrader: (4)

I have no idea where you got your pricing from but in my opinion you are way off. Its highly unlikely most on this board could get 10-12, even with low mileage unless they dumped a ton of cash into their car. Your area must be different, in my area they top out at 8, most coming in much less. This is why there is a resurgence of a younger crowd on this board. In my opinion the high of 18 with a 100k is too much(big money)for a car that has more than likely been spirited driven at least, or driven hard probably.

spawne32

iTrader: (2)

Yeh not sure where you are getting those prices at, most of the GP GXP's in the tristate area here are going between 5-8k, I bought mine for $1000 with a blown trans, in otherwise good condition cosmetically. G8 GT's go anywhere from 10-15k depending on the mileage. As far as gas mileage goes, the GXP was averaging around 16.5 city bone stock, i average around 11.5 city and 21.5 highway right now with a cam and other mods. But that stands to improve as I tune it better. I would expect the G8 to get better mileage more indicative of a RWD v8, even if you plan to mod it. My buddies GTO see's around 17mpg city and 26 highway.

rottonj

iTrader: (4)

I am very happy with the mileage on mine. It averages 21.6 on my weekly commute(1/2 highway where I drive between 65-70 and 1/2 all back roads with many stops and hills). I have seen 32 mpg on a trip a few times. I have to question if a G8 with the bigger motor,200 lbs heavier even with the same gear ratio could even come close to that. In March when my transmission was acting up I was ready to say **** this car. I looked online and classifieds in my area for all ls4 cars and saw not one over 7999. I just said after that I would keep it as even though mine is very clean and the tranny was pissing me off to me its worth more than that. I don't really need the 4 door anymore as my oldest is out of the house now , but nothing really thrills me anyway that's new(well maybe a Hellcat Challenger)

spawne32

iTrader: (2)

its an efficiency thing, part of the thing i mentioned about the stall converter being so crappy for gas mileage on these cars. A 6.0 G8 can cruise and never get above 1500 rpms to accelerate unless you need to stomp on it, this is something i was hoping for when I picked the converter using the catalog values of 1900-2100 for mine. That's what makes the difference between good gas mileage and ****. Your still seeing the advantages of DoD as well. :p but in a truely city environment, im talking like, city streets of philly. Stop and go stop and go, gas mileage sucks.

elephantrider

iTrader: (2)

g8 gt all day.

rottonj

iTrader: (4)

I wasn't questioning your mileage, your car is modified with a cam and stall and is still very respectable. Try getting good gas mileage out of older cars , real tough lol. I just don't think the G8 gets better than our cars. As I said bigger motor, 50 more horse and closer to 400lbs heavier, that doesnt add up. The gear ratio's are the same as ours on the GT also. I think real world driving it isn't even close.When I was working 6 day weeks a while back I could get over 360 miles to a tank commuting. While I don't drive aggressive, I think I could do even better(I might have to give this some real consideration to see what max could be driving like a wuss lol)

spawne32

iTrader: (2)

lol its not the mods or the displacement, its the converter, im tellin you. The thing the G8 wont have to do is have to rev to 2500 everytime you touch the throttle. That's what eats up my gas mileage. Also as a comparison for the G8 GT vs a stock GXP... gear ratios...

at 80mph the G8 GT can cruise at 1900rpm or lower with the TCC locked, the stock 4 speed on the GXP with 2.93 gears cruises at 3300 minus the TCC lockup at 80mph, its not even a comparison. The 6L80E is superior. 4 speed unfortunately is just an old technology that doesnt help gas mileage at all.

rottonj

iTrader: (4)

I don't understand. are you comparing your car with the high stall converter to the G8 or mine that is all stock? I will have to check some time but 3300 rpms at 80 mph seems really high.

spawne32

iTrader: (2)

That's a 4t65e vs a 6L80e with the converter unlocked, with calculated ratios vs tire size input with the final stock final drives. With the converter locked the RPM is probably a couple hundred RPM lower at 80mph which is probably what your used to seeing. Leave the converter unlocked and that is what you will see at 80mph. The 6L80 has a major advantage of having 6 gears, its quicker off the line, it doesnt have to work as hard to move the car, and it can cruise at a much lower RPM with a 5th and 6th overdrive gear. 6th being a better ratio then our 4th. Not to mention the converter is alot tighter on the 6L80E, 1600rpms and your rollin just fine, especially with the 6.0 in front of the trans. Take notice next time your driving for me, when you push on the gas going up hill slightly, what RPM does it rev to before the car starts to roll, or if you mash the pedal to the floor, what rpm does it rev to before it downshifts. I betcha its alot higher then you think. If i mash the pedal to the floor Ill rev to 3500, downshift, and then accelerate, it all happens very quickly but thats the high flash of a converter that stalls close to 3k. With a performance built converter I want something indicative of the rear wheel drive cars, when I mash the pedal to the floor, I want it to rev to around 2400 or so, not to mention the fact that I want it to start accelerating below 2000rpm.

I talked with circle d about this yesterday and they can do what I am asking for, i just gotta muster up the will power for a swap like that again.

spawne32

iTrader: (2)

oh **** my bad i read that chart wrong LOL hold on

spawne32

iTrader: (2)

ok so the 4t65e @ 80mph would e roughly 2100rpm unlocked, and the 6L80e would be roughly 1900rpm unlocked, and figure a converter drop of about 300rpm. I shouldnt be doing trans math when im tired. :x

rottonj

iTrader: (4)

Interesting, I will check it out. I think its lower rpm that our stock converter moves the car than what you are saying but I will confirm. I don't really pay that close attention. Did you drive your car with the stock converter?

rkhodges21

Like I said by bluebook values, the cars should be around $8k in middle TN, but there are not many listed on Craigslist in Nashville right now, so most of them are at dealers which would explain the price tag I assume. I did find one GP GXP with 110000 on the odometer listed for $5200 and I thought that was reasonable.

spawne32

iTrader: (2)

nah, when i bought it, it was trashed remember. It's possible that the increase in power is softening it up a bit, but dave said its typical of what he expects of a JTFM by what i described. I'd be curious to see how yours behaves. If i get some free time and open road where i wont get a ticket, ill take some video so you can see how soft it is. The car may pull like a freight train in the high rpm, but you can rev that bitch to the moon just by tapping the pedal to the floor real fast and the car wont respond to it, thats how soft it is. I want this thing to snap your neck when you punch the throttle, its doing just the opposite. You can tell the STR is very low on these converters.