**** yeah. i had a vq35 altima and a vg30 max. i beat the **** out of those things...

no cps failures, no overheating problems, no cracked exhaust manifolds, way better mileage, better power and torque...loved the vq.

Can you link a source for that theory? I'm not doubting, I'd just like to read about the methodology regarding stroke vs. NOx emissions. Data, not conjecture.

My opinion of space-efficiency over any other reason for the move from straight sixes to V6s is based on decades of following automotive industry trends and it's supported by many publications...

"The length of the straight-six was not a major concern in the older front-engine/rear-wheel drive vehicles, but the modern move to the more space-efficient front-engine/front-wheel drive and transverse engine (left-to-right versus front-to-back) configurations in smaller cars caused the much shorter length of the V6 (one half the length of an L6 with the same bore size, plus the width of one rod) to become a major advantage. As a result, in recent decades automobile manufacturers have replaced most of their straight-six engines (and many of their V8s) with V6 engines
"Why has the I6 gone by the wayside? Lots of reasons. A V6 is a lot more compact, and most manufacturers use engines across their entire brand lineups. That means a modern V6 engine has to fit both transverse and longitudinal applications" Source: The Truth About Cars

So far, I've been unable to find anything supporting NOx emissions (or any emissions) as a root cause (or even contributing factor) to the demise of the I6. However, a general move to smaller displacement and thus, more efficient, engines has certainly had an influence but that applies to any large displacement engine regardless of cylinder arrangement.

The way I see it, Nissan is the only company that can make a good V6. Look at all of the Z cars after they dropped the I6 in those, and the new GT-R. Its massive twin turbo V6 is still not as cool as the RB I6 but over 500HP from a 3.8L V6 is damn impressive

the chrysler 4.0 i6 has never made the wards top ten engine list. ever. the bimmer i6's, toyota 2jz i6, and the nissan rb i6 are far superior. jmho.

I think much (but not all) of that is due to what those engines were used in. I don't think they're "far superior", though, just part of a more universally praised vehicle. Had Chrysler continued to refine the 4.0L I6 and broaden it's application beyond utility vehicles (eg, Crossfire and Sebring) it might have garnered more attention from Wards. But they didn't, they stuck with an iron block and head and stuffed it in a bunch of big, clumsy solid-axle boxes on wheels with no more performance aspirations than a farm tractor. This is also jmho.

That's due to the Drive By Wire system. There's NO throttle cable, its all sensors n ECU.

Also the reason that yotas were spontaneously accelerating.

i agree with you in part. but refinement of the 4.0 would have ultimately led to something more along the lines of one of the import i6's anyways...less stroke, free reving, aluminum head, overhead cam, variable timing...

even the old naturally aspirated 7m engines which went bye-bye in 1992 were a better engine than the the 4.0...imo. i had a na supra, and a turbo. they were both heavier than an xj, but had plenty of torque down low.

although max torque comes on 1000 rpms sooner in a 4.0, i still dream of stuffing a 7m or 2jz into an xj...

maybe i'm kind of partial lol

My commander has that delay when you floor it. I didnt buy either of my jeeps for racing though. I bought them to get me where I need to go.

You can actually eliminate that delay with these plug in chips.

Ok... couple things here... Chrysler dropped the 4.0 because it is NOT A CHRYSLER ENGINE... it is AMC, chrysler tampered with it, then decided to hell with it, we didn't invent it anyways. chrysler does NOT produce anything else that comes close in terms of durability... PERIOD

Second... shorten the stroke? Yeah, you should've kept the ricer... longer stroke = more TORQUE, shorter stroke = higher rpms. This a 4x4, no a candidate for the next fast and furious movie...

And a list from a publication? pffft, country boys who actually use this stuff don't have publications... we'd rather be using it some more.

Lol on the last part but only the Renix 4.0 was AMC Chrysler had the HO 4.0 that's the design change. The Renix was just a destroked 258 (4.2L for you OCD metric *****) fitted with fuel injection and various Chevy n Ford (True AMC fashion) electronics. With the HO (Highly Overrated), all the electronics n parts were ChryCo.

It plain and simple. The 4.0L was discontinued because it could not keep up with EPA standards.

It's not the rest of the USAs fault that California has smog! EPAs thought process.."Oh the people of California live in a smog filled valley, let's put stricter regulations on the rest of the US to keep California's pollution levels lower." WTF?!

Isn't it to keep the rest of the us from being like cali? Lol