3.42 or 3.73 gears

jaslo · January 22, 2006

Hi everybody, we are possibly looking at a new pickup. Was wondering if getting the 3.73 gears make that much of a difference in gas mileage compared to the 3.42. Also looking to get 4 wheel drive in a crew cab.

redvett · January 22, 2006

Hi everybody, we are possibly looking at a new pickup. Was wondering if getting the 3.73 gears make that much of a difference in gas mileage compared to the 3.42. Also looking to get 4 wheel drive in a crew cab.

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3:42 will slow down the engine (improve fuel economy) but you will lose a bit of performance. You didnt say where your located and if you tow or if your in hilly country. They are a factor when selecting a gear ratio.

jaslo · January 22, 2006

Hi everybody, we are possibly looking at a new pickup. Was wondering if getting the 3.73 gears make that much of a difference in gas mileage compared to the 3.42. Also looking to get 4 wheel drive in a crew cab.

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3:42 will slow down the engine (improve fuel economy) but you will lose a bit of performance. You didnt say where your located and if you tow or if your in hilly country. They are a factor when selecting a gear ratio.

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I live in central part of Missouri, where its a little hilly but not that bad.

pm26 · January 22, 2006

I went with 3.73 gears on a crew cab 4X4 truck, and I am in flat country(Florida). In my opinion, this is the best choice for all around use, and occasional medium duty towing. If you intend to do a lot of towing or off-roading, get 4.10 gears. 3.42 gears are too tall, and will cause the truck to accelerate more sluggishly from a standing start. Until 2005, 3.73 gears were standard in all Z71 crew cab trucks.

Then somebody at GM decided that they could show higher sticker mileage by using 3.42 gears. 3.42 gears do not belong on a crew cab 4X4 truck that is being used as a truck. They use them strictly to boost the mileage ratings. But do not take my word for it: if you order the Vortex Max package, you get 3.73 gear standard on a two wheel drive truck, and 4.10 gears standard on a 4 wheel drive truck. That should tell you something.

redvett · January 22, 2006

The guy wants gas mileage and probably wont spend $3000 for the Vortex Max package and lower mileage. I wouldnt.

BTW GM does not have control of EPA fuel mileage and all MFR's have to increase fuel economy by .5% per year starting in 2005.

lrymal · January 22, 2006

My '05 Z71 has 3.42s. My '03 Z71 has the 3.73s.

Because of the way the power band is, I guess, my '05 Z71 is faster in all ranges than my '03. It gets abouts 3 MPG improvement over my '03, but there's other improvements as well over my '03's design.

For towing in the hills, I have to have the '05 in 3rd most of the time, not as much in 3rd with the '03.

This seems to be a religious argument with a lot of enthusiasts. For trucks that barely knock on the 20MPG gasoline door, a 3mpg improvement really doesn't matter that much. Both the 3.73 and 3.42 tow rather nicely, provided you don't insist on using "D" all the time.

I'd take either the 3.73 or 3.42, as determined by whatever options you can get for the least amount of money.

And, if you intend to do quarter-mile racing, then you need to get 4.11s or similiar. Just don't buy your gasoline from Citgo. ;>)

jaslo · January 22, 2006

I dont plan to do much towing, besides this would be the wife's truck anyway.

redvett · January 23, 2006

I dont plan to do much towing, besides this would be the wife's truck anyway.

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I would go with the 3:42 its great for economy and your wife wont ever know the difference.

fossil · January 23, 2006

I've got a 2005 model 4x4 with the 5.3L. It's got 4:10 gears and it consistently gets 24mpg highway and 19mpg city. That is on an imperial gallon by the way and not a us gallon. At 110kph the engine revs out at 2100rpm.

pm26 · January 23, 2006

You get a lot better fuel economy with a smaller truck like Colorado, if it is just for commuting.

lrymal · January 23, 2006

I've got a 2005 model 4x4 with the 5.3L. It's got 4:10 gears and it consistently gets 24mpg highway and 19mpg city. That is on an imperial gallon by the way and not a us gallon. At 110kph the engine revs out at 2100rpm.

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I oughta be able to do this:

1 imperial gallon = 1.2 US gallon

1 kilometer = .62 miles

So, he goes 66 miles per hour at 2100 rpm. If I remember correctly, I go 70 mph at 1800 rpm. I might be wrong.

But, my brain won't do the US mpg conversion. I'm getting too old for this stuff!

Crabhart5.3 · January 23, 2006

I oughta be able to do this:

1 imperial gallon = 1.2 US gallon

1 kilometer = .62 miles

So, he goes 66 miles per hour at 2100 rpm. If I remember correctly, I go 70 mph at 1800 rpm. I might be wrong.

But, my brain won't do the US mpg conversion. I'm getting too old for this stuff!

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Well i have 3.42s and my rpms at 70 are 2k on the dot.

OUMike · January 23, 2006

Yea...3.73s here. I wanna say 70 mph gets about 2 grand also. Like 2300 or so.

4.3 gets me 20 mpg hwy (@ 200k miles).

I also vote for Colorado for daily communter.

Buggle_96 · January 23, 2006

My '05 Z71 has 3.42s. My '03 Z71 has the 3.73s.

Because of the way the power band is, I guess, my '05 Z71 is faster in all ranges than my '03. It gets abouts 3 MPG improvement over my '03, but there's other improvements as well over my '03's design.

For towing in the hills, I have to have the '05 in 3rd most of the time, not as much in 3rd with the '03.

This seems to be a religious argument with a lot of enthusiasts. For trucks that barely knock on the 20MPG gasoline door, a 3mpg improvement really doesn't matter that much. Both the 3.73 and 3.42 tow rather nicely, provided you don't insist on using "D" all the time.

I'd take either the 3.73 or 3.42, as determined by whatever options you can get for the least amount of money.

And, if you intend to do quarter-mile racing, then you need to get 4.11s or similiar. Just don't buy your gasoline from Citgo. ;>)

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Agree 100%. It seems like all the guys who knock on the 3.42's seem to just think it would be a dog. Its a totally different truck, yes it does pull a taller gear, but hearing and feeling that HO pull on those gears is just like the LS1 in my moms WS6 Trans Am.

Its quite impressive how well this truck does run. And I have no problem towing, tow at 70 and it sits at about 2700 rpm in "3" right in the engine powerband. It actually tows better at 70 with a good load than it does at 65 or 60 simply because its not in the power band yet and only runs around 2300 rpm.

I know, i know 4.10's would haul better but I am just saying 3.42's give these trucks a different feel not a slower or underpowered feel. On a side note I got the Wait4me tune done and I do about 1600 rpm at 65. It does around 2k at 80mph. I dont know how Jesse lowers the torque converter lockup point, but the tach shows it.

ProSport Tim · January 23, 2006

Will towing in "3" actually do anything negatively to the vehicle for long stints? I'd imagine it would only be good for a truck w/ 3.42's as the tranny isn't suffering with consistant shifting to maximize power. I have the 3.42's/5.3HO and while I'd prefer 3.73's the motor does pull them nicely. After 2500 it's a blast up to 5500(the stock rev limiter is way to low with the 3.42's, IMO). If you live in a flat area go with the 3.42's, if it's hilly 3.73's. I think by having the 3.42's in a hilly area, the constant shifting(more gas burned) negates the benefits for fuel consumption w/ lower gears.