- TrailBlazer and other GMT360 SUVs are the only ones that use the 4.2L I6 and they are going away.
- GMT900 Silverado's use the old 4.3L instead of the DOHC 4.2L I6
- Colorado's 3.7L DOHC 5 cyl. puts out less HP and Torque than GMs new 3.6L DOHC V6's
- The DOHC 3.6L is used in Holden's version of the Colorado

On the plus side:
- The 2.9L 4 cyl. Atlas used in the base Colorado's has class leading power and damn good fuel economy. But does anyone care about 4 cyl. pickups? The Ecotec 2.4L isn't too far behind in power. How big can they make an Ecotec?

I don't know what is planned for the future of this engine line, but based on what info is public it doesn't look good.

 

Good questions. I can't even hope to answer that.

I will say that the Trailblazer isn't going anywhere for at least the next few years.

Wonder if the 4.2 I6 would fit in the new Zeta Impala.

 

If only that would happen I think the Ford Aus 4.0T I6 would be much less of a powerplay for Ford to bring to the US.

What if the RWD Caddys got the 4.2 I6 vs the non Caddy RWD cars getting the 3.6 V6? That would elevate the Caddy cars quite a bit (IMO), more power and smoother than the 3.6. Also it would be more BMW like for Caddy to do.

Imagine what the 4.2 could do with dual VVT (it only has it on the exhaust side right now), DI, and a 6 speed auto or stick! Much less what a Turbo model could put out!

 

I would question the packaging of the 4.2 I6 in any car. On the 4wd GMT360's one of the front drive axles passes through the oil pan. I'm thinking this would be especially tough to package in a car body.

 

Whaaaaaaat? Other than the fact the 4.2 is a big lump of a truck motor which really won't package well in modern cars.......

Caddy just plain would never replace it's HFV6 with a truck motor regardless of packaging.

And please, you can not compare an I6 truck motor with BMW's inline sixes.

 

Lets see the 4.2 is much taller and right now only can be put in vertical only. The 4.2 is likely just as smooth as the 3.0 BMW I6 it puts out similar power numbers and likely would get as good or better gas mileage. Forget the truck motor stigma. Heck, take the engine out of production a year, make the changes to put it in at an angle. Though it would likely not need it because it is probably not taller than the N* and is only 3" longer than the LSx engines (which the N* is probably just as long.) That all being taken into consideration what makes it unsuitable for a car application? It is tall, but could be repackaged, is powerful, is smooth, is VERY modern, is VERY good in fuel economy. So why is it not suitable again, stigma aside?

 

Uhh, I would say you're probably off your rocker to assume that. No offense, but the 4.2 was developed for use in a truck....thus Charlie's references to the same....Do you really suppose the characteristics of this motor are anywhere close to those of the motor in a German sports sedan? The 4.2 is a nice motor for what it is but come on. The fact that both of these motors are inline-sixes is where the similarities end.

Well that's interesting. I thought the TB was dead in the foreseeable future. I'm glad to see it will get a stay of execution, but my biggest question is, will it continue on unchanged? They have got to do something about that interior, at least....

 

I don't have the engine dimensions at my fingertips, but last I checked the 4.2 had packaging issues (for cars), BOTH because of it's height AND length. To put this packaging thing into perspective, the CTS-V got the LS6 instead of the Northstar because of a clearance issue of slightly less than ONE inch.

As far as the 4.2 being as smooth as a BMW I6.........ummmmmm......are you kidding me? Go now, right now, and drive both and come back and report to us.

 

You're not speaking my language here, Charlie. Is the small block V8 not a worthy car motor because it is used in trucks? What about the 4.4 and 4.8 L BMW V8s? After all, they are used in the X5. Does that mean they are too crude for the 7 Series? Evidently BMW (and the auto scribes) disagree.

The 4.2L may have been used in the TB, but it was developed because the line between cars and trucks/suvs is almost gone. Buyers demand power and refinement in SUVs as well as cars.

The 4.2L is a world class engine. All aluminum, DOHC, 24 valve, VVT, and so on. Extremely smooth and powerful. If it first showed up, exactly as is, in a replacement for the Caprice (and then moved to the suvs), people would have been drooling. The fact that it is used in the TB/Envoy does not make the engine any less competent or refined.



It isn't a "truck" engine any more than the new 3.5L toyota engine family (used in the IS350, the Camry, the Avalon, AND the RAV4, with lots more to come) is a "truck" engine b/c its in the RAV4. Or the BMW or MB V8s. And so on...

 

No Joe, that's not what I'm trying to say. The 4.2 is a nice motor, but comes up short in certain areas for Cadillac to start replacing it's powertrain line-up with it. That's what I'm trying to say. And comparing it to the personality of a BMW I6 is completely off base - there simply is no comparison.

Hell, even the HF 3.6 in my CTS is a notch below BMW in refinement. In fact, I'd even put it 1/2 notch below the Duratech V6 in my SVT Contour. The Duratech is much smoother, both at idle and high RPM.

 

I was just going to make the same points.

Using the "Truck Engine" argument in today's market just doesn't hold water anymore.

Last I heard, I could get a truck engine in a Corvette. Been that way for at least 10 years.

What's the engine in a Cadillac CTSv but a modified truck engine???

 

I'd say most of the "personality" difference is in the tuning. I mean, the 4.2L has been tuned to deal with the mass of a 4700 lb SUV. If it were tuned to be more car like, with say 320 hp and 275 lbft (much like a BMW engine), with the appropriate intake and exhaust tuning to match the right sounds, you'd never know it was first used in trucks. Inline sixes have basically perfect primary and secondary balance. Couple that with the rigid, deep skirt block, structural oil pan, direct mount accessories, and so on, what exactly about the BMW makes it smoother (as in less NVH)?

As for the duratec being smoother than the 3.6L, I don't know what to say. Maybe it was better in the Contour. But it has been criticized for being rather hoary in recent Taurus tests I've seen (and I think maybe 500 and Fusion, for that matter). I drove an Escape for a week with the 3.0L, and found it to be rather unsatisfying from an NVH standpoint (as well as power output).

I think a lot of what we (and the magazines) call a lack of "smoothness" might really just come down to intake and exhaust tuning, not actual vibrations given off by the engine. Especially with an inline 6 in a TB. When I've driven a vehicle with the 4.2L, I found it to be extremely smooth, but I didn't care for the sound effects because the exhaust sounded rather asthmatic. Put a more BMW-like exhaust on it, with appropriate intake resonators to tune the intake sound effects, and drop that 4.2L into an X5. I bet you'd never tell the difference.

Back in the day, engines had sheetmetal oil pans that acted like speakers, accessories mounted on flimsy brackets that allowed all sorts of vibrations at various frequencies, and so on. Newer engines don't do that anymore...

 

Yeah, because they let 25 year old college students test drive BMWs all the time!

As far as smoothness in its current state sure it would be different in a sports sedan vs a truck.

 

I agree that if GM were to go through the 4.2 and convert it to passenger car use, they'd have a much more refined, much more sporty piece - and I'd actually be excited to drive such a package. But of course, they'd have to go to the effort of doing that first. And it still remains to be seen how it would compare to a BMW I6 (which was my original point)....... and .....if it would even fit a car.

As far as the Duratech and the HFV6, at idle, on my SVT, if you didn't hear the exhaust burbling, you wouldn't even know it was running. On my CTS the whole car shakes at idle (I understand there's a TSB out for it). Also, on my SVT, I can kiss the rev limiter with velvety smoothness, where revving my CTS over 5,500 gives me alot of harshness. But like you said, it could be secondary to tuning - the CTS has a very restrictive intake for example, which could be contributing to that higher RPM thrashiness.

 

The smallblock was designed for BOTH passenger car AND truck use, the 4.2 was not.

Gotta get to work, I'll check back later..........