2004 5.3 3:73 Vs New 1500 6.2l 3:73 6spd.

[WilliamBos]

Hey Guys,

 

Am curious about a comparison between my current ride 2004 GMC CC 5.3L 3:73 Z71 vs a new GMC 1500CC 6.2L 3:73 Max Trailering?

 

Performance? Economy? Over all truck??

[RyanbabZ71]

Old: 2000 Ext Cab Z71 5.3 3.73 rear

New: 2010 CC Z71 6.2 3.42 rear

 

Power: 2010

Performance: 2010

Overall: 2010

Milage: Same for both dont see a major difference actually.

[Matt_]

holy crap man... if you're even thinking about it... just do it!!

 

Seriously, the power/performance/towing/driveability all go to the new truck and mileage is about even...

[uh6tdrvr]

is this seriously a question? how about 100+ hp difference?

[dogzapper]

Slightly different subject:

 

I own a 2004 Tahoe LT 5.3 - 3.73. It has been a great little truck; adequate power and tows our 5,000 pound trailer house reasonably well. The economy is decent; unloaded city 13 mpg and highway 18 mpg ... towing our trailer = 8-9 mpg.

 

We still own the Tahoe and will probably drive it until it dies ... only 27,000 miles on her, so she has many years to go.

 

Enter the new truck: Our 2010 5.3 - 3.42 with the 6-speed transmission. HOLY CRAP, the new rig just simply blows away the 2004 Tahoe in every department. The current 5.3 engine is way snappier than the 2004. I know that I've picked up maybe 30 horsepower and the 6-speed just plain optimizes the power curve, but this truck is waaaaaay beyond the old Tahoe in performance.

 

And the fuel economy of my new 2010 Z-71 absolutely blows away the 2004 Tahoe. Unloaded, I'm getting an honest 15+ mpg around town and have yet to get under 20 mpg on the freeway (even one full tank at 21.1 mpg hand-calculated). Pulling the same trailer, my one experience netted 11.9 mpg AND the engine VERY easily pulls the trailer.

 

Comparing the 2004 combination of 5.3-liter engine with the 3.73 rear end and the available transmission ... versus ... the 2010 5.3-liter engine with the available 5-speed tranny and the 3.42 rear end; Man, there is absolutely NO comparison. The 2010 is lightyears ahead of the 2004.

 

 

Had there been a Victory Red Silverado LTZ with all the goodies I wanted, plus the 6.2-liter engine, available when I was shopping a month ago, I certainly would have bought that puppy in a heartbeat. Absolutely, I would have bought the 6.2.

 

Am I in the slightest bit disappointed with the 5.3 / 6-speed / 3.42??? Nope, I'm totally delighted with it. I'm thinking that a great amount of that peppiness possibly comes from the 3.42 rear end.

 

Interestingly, there aren't many 3.42 rear ends available in our area (Portland, Oregon). I'm wondering if the much more common 3.08 rear end would still be on the side of happiness ... or if it turns the rig into a turd.

 

I don't know, but I would be interested in that.

 

So, Hell yes, buy the 6.2 if you can find one. Personally, I'm finding the 5.3 / 6-speed / 3.42 to be a fabulous combination.

 

Steve

[music]

Unloaded, I'm getting an honest 15+ mpg around town and have yet to get under 20 mpg on the freeway (even one full tank at 21.1 mpg hand-calculated).

 

FWIW, I get those same numbers w/ a 2008 5.3/4-spd/3.73. I agree on the 07+ 5.3 --- I felt the difference over my 99 immediately... even with the more aggressive e-nannies. Towing w/ the new truck was much better, with noticeably better power, stability and braking.

 

To the OP: re: economy differences between the two, I'd use the EPA numbers... as they seem about right. The 6.2 numbers are with premium fuel, so I'd deduct some from those numbers if you plan to run 87. Still, it should put out more than 10% better torque over the 5.3 on 87 octane (wild guess), but it's not going to be as economical overall. For towing, the 6.2 gets the 14 bolt rear axle w/ disc brakes, so it definitely has the edge all-around for raw performance. Whether you need it and how you feel about the overall cost difference is a personal decision.

[WilliamBos]

Thanks alot.

 

Can the 6.2 be run all the time on regular gas?

 

Unloaded, I'm getting an honest 15+ mpg around town and have yet to get under 20 mpg on the freeway (even one full tank at 21.1 mpg hand-calculated).

 

FWIW, I get those same numbers w/ a 2008 5.3/4-spd/3.73. I agree on the 07+ 5.3 --- I felt the difference over my 99 immediately... even with the more aggressive e-nannies. Towing w/ the new truck was much better, with noticeably better power, stability and braking.

 

To the OP: re: economy differences between the two, I'd use the EPA numbers... as they seem about right. The 6.2 numbers are with premium fuel, so I'd deduct some from those numbers if you plan to run 87. Still, it should put out more than 10% better torque over the 5.3 on 87 octane (wild guess), but it's not going to be as economical overall. For towing, the 6.2 gets the 14 bolt rear axle w/ disc brakes, so it definitely has the edge all-around for raw performance. Whether you need it and how you feel about the overall cost difference is a personal decision.

[RyanbabZ71]

Thanks alot.

 

Can the 6.2 be run all the time on regular gas?

 

Unloaded, I'm getting an honest 15+ mpg around town and have yet to get under 20 mpg on the freeway (even one full tank at 21.1 mpg hand-calculated).

 

FWIW, I get those same numbers w/ a 2008 5.3/4-spd/3.73. I agree on the 07+ 5.3 --- I felt the difference over my 99 immediately... even with the more aggressive e-nannies. Towing w/ the new truck was much better, with noticeably better power, stability and braking.

 

To the OP: re: economy differences between the two, I'd use the EPA numbers... as they seem about right. The 6.2 numbers are with premium fuel, so I'd deduct some from those numbers if you plan to run 87. Still, it should put out more than 10% better torque over the 5.3 on 87 octane (wild guess), but it's not going to be as economical overall. For towing, the 6.2 gets the 14 bolt rear axle w/ disc brakes, so it definitely has the edge all-around for raw performance. Whether you need it and how you feel about the overall cost difference is a personal decision.

 

 

It is suggested you run premium or E85. You can run regular but will see a performance decrease

 

I run the corn fuel and it runs great

[jblakeney]

Yea,

 

I've been tossing the same idea in my head tooooo. I would like to have a new truck.. My 1999 is still the best thing I have ever drove in my life.... Less a couple BMW's........ But I would not own a BMW.....

 

When the 6.2 goes AFM on the trucks I will not buy a GM truck (V-6 is not an option with me). So I have been looking well shopping. I hear from a couple of friends that they got just a couple mpg's better than their trucks that were like mine.

 

With a 2010 I know I will be upgrading the bumpers day after purchase. 3 piece bumpers wft thats all I have to say about the OE bumpers?

 

Jbo

[RyanbabZ71]

[ATMINF]

The onther main point is that the 6L80 trans is a much better trans than the 4l60 series of trans that it replaces. That it in itself is a huge improvement. And then if you want the 3/4ton, the 6l90 is pretty beefy itself, and the plus side is that the trans allows you to run a lower gear 3.73 vs. 4.10, which should get you better gas milage.

[WVMountaineer]

Interestingly, there aren't many 3.42 rear ends available in our area (Portland, Oregon). I'm wondering if the much more common 3.08 rear end would still be on the side of happiness ... or if it turns the rig into a turd.

 

 

Not in my opinion. My short bed regular cab 2010 w/3.08 gears seems to every bit as quick (just not as much torque) as my '81 Camaro with 360 rwhp and 3.42 gears.

[WilliamBos]

Yea,

 

I've been tossing the same idea in my head tooooo. I would like to have a new truck.. My 1999 is still the best thing I have ever drove in my life.... Less a couple BMW's........ But I would not own a BMW.....

 

When the 6.2 goes AFM on the trucks I will not buy a GM truck (V-6 is not an option with me). So I have been looking well shopping. I hear from a couple of friends that they got just a couple mpg's better than their trucks that were like mine.

 

With a 2010 I know I will be upgrading the bumpers day after purchase. 3 piece bumpers wft thats all I have to say about the OE bumpers?

 

Jbo

 

Are there plans to go AFM on the 6.2? And what dfo you not like about it??

[jblakeney]

Yea,

 

I've been tossing the same idea in my head tooooo. I would like to have a new truck.. My 1999 is still the best thing I have ever drove in my life.... Less a couple BMW's........ But I would not own a BMW.....

 

When the 6.2 goes AFM on the trucks I will not buy a GM truck (V-6 is not an option with me). So I have been looking well shopping. I hear from a couple of friends that they got just a couple mpg's better than their trucks that were like mine.

 

With a 2010 I know I will be upgrading the bumpers day after purchase. 3 piece bumpers wft thats all I have to say about the OE bumpers?

 

Jbo

 

Are there plans to go AFM on the 6.2? And what dfo you not like about it??

 

 

They already did it to the Yukon Denali......... 6.2 with AFM.

 

My big beef with AFM there is NO WAY to stop the crank from slinging the rod & piston. Lifters how many sets you guys on with the AFM engines???? Oil consumption was that a quart or 3 quarts on an oil change? AFM is a waste, it does not pick the mileage up that much.

 

Jbo

[OL_FAITHFUL]

To understand the benefits of the new 6spd, you need to break down the individual gear ratios (1-6) vs. the old 4L80 (1-4) and compare old drivetrain setups with new ones, with a common power output and tire height. The quick summary is, the 6spd trucks (even with 5.3s) outperform the old 4spd trucks in every way (including GMT-900 4spd trucks).

 

6spd:

 

1st - 4.027

 

2nd - 2.364

 

3rd - 1.53

 

4th - 1.152

 

5th - 0.852

 

6th - 0.667

 

 

4spd:

 

1st - 3.06

 

2nd - 1.63

 

3rd - 1.00

 

4th - 0.73

 

For experiment's sake, we'll set tire height to 32", and motor torque output at 300ftlbs.

 

So, old school 4spd with 3.73 rear end, how much force does it put to the ground in 1st with 300ftlbs?

 

(300ftlbs * 3.06 1st gear * 3.73 rear end ratio) / ((32" tire / 2 (for radius)) * (1ft/12in)) = 2568 lbf at the taars

 

For the 6spd, 1st gear, 300 ftlbs, 3.08 rear end:

 

(300ftlbs * 4.027 1st gear * 3.08 rear end ratio) / ((32" tire / 2 (for radius)) * (1ft/12in)) = 2790 lbf at the taars

 

How about 70mph cruising rpm in top gear:

 

4spd:

 

((70MPH * 1.4667(ft/sec/MPH)* 3.73 * 0.73) / (PI * 32" * (1ft/12in))) * 60 sec/min = 2002 RPM

 

6spd:

 

((70MPH * 1.4667(ft/sec/MPH)* 3.08 * 0.667) / (PI * 32" * (1ft/12in))) * 60 sec/min = 1510 RPM

 

So, even with that dog of a 3.08 rear end, the new 6spd trucks (even with the 5.3) will out accelerate the old 4spds with 3.73s (with 5.3s), and in turn put more torque to the ground for towing. If you opt for the 3.42 rear end, you get even more acceleration and grunt. If you also place a check-mark by the 6.2L, then you have more brains than most, and will be able to hang with most stock GT mustangs from 1973-2010, because of the power benefits generated by VVT coupled with the dump truck 4.027 1st gear. The 6.2 Tahoes Chevy snuck out in 08-09 are very reminiscent of late 60s Impala wagons with 396s stuffed under the hood.

 

Also, for those that are crying over the AFM, get past it. For one, it can be tuned out, 2nd these trucks have 100k mile powertrain warranties. If you still hate AFM after 100k miles, tune it out, and put regular ol' lifters in it.