Looking at 2 identical trucks. 3.08 vs. 3.42 axle

[BobsArmory]

I am in the market for a new truck and have found 2 trucks at the dealership that I like. They are identical right down to the color except for the rear axle ratio one truck has a 3.08 rear end the other has a 3.42.

Considering both have the 5.3 liter engine and the same transmission. Would I see any real difference in economy/trailering between the 2? I wonder, at 70mph how many more RPMs I would see with the 3.42 rear end

If you had to pick, which one would you get?

 

[sciphi]

How much trailering, how heavy, and what other uses will the truck be put into? The 3.42's would make towing easier, while the 3.08's would give better unloaded fuel economy.

 

[zfasts03]

3.42 is going to be peppier off the line, also tow nicer, being the engine will be able to run at higher rpm's making more power. With a 6 speed auto and the computer always placing the trans. in the most appropriate gear for fuel economy, I don't think there will be much of a fuel economy difference.

I would test drive both, around town and highway.

If it were me buying the truck I would go with the 3.42.

My 1997 Dodge Ram 1500 4x4 has 3.92 gears. I love it's ability to get up and go off the line.

 

[rkpatt]

I would go with the 3.08 . Add a big transmission cooler if you plan to any towing or heavy hauling ( with either one ).

 

[zfasts03]

3.42 allows for opting for larger tires down the road without bogging the engine with tall gears.

 

[BobsArmory]

About 5 times a year I pull a trailer with ATVs on the back. Almost every year I get to do an out west hunting trip, Michigan to Colorado/Wyoming with a pretty good load. Other than that it's a daily driver.

the reason I am looking at a new truck is that even though my 2009 truck is great at doing what I want it to do, the 6L engine with the max trailer package is just a bit on the "thirsty side".

 

[JerryBob]

Originally Posted By: BobsArmory
the reason I am looking at a new truck is that even though my 2009 truck is great at doing what I want it to do, the 6L engine with the max trailer package is just a bit on the "thirsty side".



From a purely economic standpoint, paying the marginal cost of the 2009 fuel consumption will be far cheaper than a new truck.

 

[zfasts03]

With light throttle driving the transmission will just take second gear sooner. Yes highway RPM's in 6th gear will be slightly higher, but not by much. Light throttle on the highway will be more likely to accelerate, without having a downshift, which could be more enjoyable then having a downshift every time you want to increase speed on the highway.

Test drive both.

 

[zfasts03]

Rkpatt 3.08 what is the rationale for your choice?

 

[jmb3675]

I wanted a 3.73 in my truck but I found one that had everything I wanted except it had a 3.55 rear end. Not wanting to order one and wait for it I settled on the 3.55. It has been great for fuel mileage and likely has saved me some cash, But I still wish I had the 3.73 gears. I hardly tow and it's usually light trailers, but I still wish I had more off the line power. When I tow my buddies trailer for hunting is when I really wish I had the 3.73. I have even looked into changing them, but the cost to do both axles is more than I feel it is worth.

Unless you really care about fuel economy I would get the 3.42

 

[mcrn]

Originally Posted By: JerryBob
Originally Posted By: BobsArmory
the reason I am looking at a new truck is that even though my 2009 truck is great at doing what I want it to do, the 6L engine with the max trailer package is just a bit on the "thirsty side".



From a purely economic standpoint, paying the marginal cost of the 2009 fuel consumption will be far cheaper than a new truck.


This +1 That is a lot of gas. But if you are set on a new truck I would go with the 3.42 for sure. i believe it will be easier on the tranny and around the city is not guaranteed to give better MPGs. But seriously think about the money you will spend on a new truck and think about how much fuel that is.

 

[BobsArmory]

Originally Posted By: JerryBob
Originally Posted By: BobsArmory
the reason I am looking at a new truck is that even though my 2009 truck is great at doing what I want it to do, the 6L engine with the max trailer package is just a bit on the "thirsty side".



From a purely economic standpoint, paying the marginal cost of the 2009 fuel consumption will be far cheaper than a new truck.


14.5 MPG for the 6 liter vs. 22 MPG for the new 5.3 liter. I drive at least 50 miles per day plus I get a GM Employees Discount but I am still plugging those numbers in to see what the difference would be.

 

[jmb3675]

Originally Posted By: JerryBob
Originally Posted By: BobsArmory
the reason I am looking at a new truck is that even though my 2009 truck is great at doing what I want it to do, the 6L engine with the max trailer package is just a bit on the "thirsty side".



From a purely economic standpoint, paying the marginal cost of the 2009 fuel consumption will be far cheaper than a new truck.


I just saw this after I made my last post, and I have to agree. The cost of a truck payment should be able to buy a few gallons of gas.

 

[zfasts03]

The engine is still doing the same work, moving the same mass, fuel economy #'s may not vary depending on style of usage. I would buy the truck that drives nicer. I know this is subjective, but characteristics of 3.42 is more desirable to me. My personal opinion and experience with my 3.92's on my Dodge Ram.

 

[mcrn]

Originally Posted By: jmb3675
Originally Posted By: JerryBob
Originally Posted By: BobsArmory
the reason I am looking at a new truck is that even though my 2009 truck is great at doing what I want it to do, the 6L engine with the max trailer package is just a bit on the "thirsty side".



From a purely economic standpoint, paying the marginal cost of the 2009 fuel consumption will be far cheaper than a new truck.


I just saw this after I made my last post, and I have to agree. The cost of a truck payment should be able to buy a few gallons of gas.



I also just saw this after my last post. I agree. Good idea to look into this.

 

[demarpaint]

I'd pass on the 3.08 especially if you're going to tow. The 3.42 will be better in every regard IMO. The only trade off is a slight hit in mpg, hardly worth it IMO.

 

[jmb3675]

At least in my experience, when working a vehicle harder, having more power saves gas. One example is My Focus with a 2.0 4cyl driving it hard, which I love to do, I get 22-23 miles per gallon. With the Malibu with a 3.5 v6, I got 25-26 driving it hard. In my case, the bigger car with more power got better mileage. I do miss that car.

 

[mrsilv04]

Had a GMC Van with a 305 and a 3.08 rear end.

Granted, that was a bad combination, and the idiot at the GMC dealership that ordered it should have been slapped.

However, it would barely push anything in reverse.

I have a 3.42 in my Siverado, and a 3.73 in my Sierra... both with 5.3 engines. I like the 3.42 best.

 

[supton]

That 305 had the 4spd auto, not sure if your 5.3's had the 4 or the 6. Makes a huge difference. The 4spd had a 3.06:1 first gear, the six runs with 4:1. And has more ratios between gears too, rather than big ratio jumps.

I'd vote for the 3.42, if not keeping a known good truck and buying an econobox .

 

[eljefino]

Get the 3.42s. They'll be rarer and might be worth more in resale later. I curse the moron that put 2.73s in my F150.

When you're shopping for used trucks, to use as trucks, tall gears are all over the place.

It'll be easier on your tranny and u-joints too... less load, albeit with more spins.