Hi all,
I realize it has been ages since being on the forum, but that is because our 6cyl Envoy has been remarkably good to us.
I am wondering something:
My Envoy is a bit sluggish when pulling our trailer, naturally. I have a weight distribution hitch, and it does fine in a straight line, but has trouble when towing up hill. It will gear down and do it, but it's a Little Engine That Could kind of thing.
Currently I see a V8 Envoy for sale and am wondering about their reliability, and if it's towing capability is far greater than what I have? I am thinking the V8 will almost be better on gas, as it won't have to work as hard. It has about 350,000km on it, which is a bit high, on the other hand, my 6cyl Envoy is around the same.
Curious to know your thoughts, experience. Thanks!
Adam
I can tell you're an infrequent visitor / poster, if you haven't seen my 'Towing heavy objects up the Black Hills' thread...lol. Do a scan on my posts, and you'll come across it - it's not old.
I have the 'holy grail' for GMT360 / 370 towing - 2003 LM4 in XL/EXT, 3.73 gear. I say 'holy grail' b/c it was the highest rated of the entire run, towing capacity-wise. 7000 lb in 4WD (+200 in 2WD). WDH above 4K, with a max tongue of about 900 or so. I forget the payload #, but it's easy enough to find.
Now, part of that rating wasn't because GM put anything 'extra' in the 2003-2004, but more because GM revised their tow ratings after then, and everything went down a bit (not just the 360s). Since the '05-ups got a small HP/TQ boost with the LH6 (but also gained AFM), 'real-world' numbers might even be better than my 7K rating. But I'd never advise you do that, from a liability standpoint (seriously).
My engine is stock. The trans was rebuilt a couple of years ago with towing in mind (still a 4L60e; if I had spent the money for a front / rear planetary upgrade, it would technically be a 4L65 - but I didn't). I also have a +10000 BTU trans cooler. Other than that - stock (with a lot of new parts to get her back to spec, maintenance-wise). About 240,000 KM on the clock; mine's not a daily driver.
My rig is a 25' trailer (you can see pics of it in the thread I listed above). Dry weight is 4000lb; last time I weighed at the CAT scales, it was about 5500lb or so (the trailer is rated for just over 7000lb, so it's a nice complement to my Envoy XL.) I do use a WDH w/ adjustable sway control, and if I don't hook up the bars, she will sag noticably in the rear. I have the coil springs in the rear (no self-leveling / air bags)
Now...the part you're interested in...how does she tow?
I'll admit, I'm kind of biased (never owned a 4.2L), but until I started getting into steeper elevations / grades during that trip (above 5000ft / 6% or steeper grade), I never complained about what she had to give.
Based on what I know of the 4.2L, you'd probably gain +15% on the power end. I tow in 3rd (you should, too), and I don't exceed 65-70mph, because that's what the trailer tires are rated at. I also am mindful of what it takes to safely bring down +10000 lbs at speed.
It's absolutely great on flats / smaller hills. But if you're gonna climb the BIG mountains with regularity, you'll find yourself back in 'little engine that could' territory again. Depending on how serious you are about towing, it would be time to look at power adders (turbo, supercharger). That's where the V8 would really shine, as the LS engine family has *so* much aftermarket support (and it will handle those additions well, as long as you're not looking to go nuts - you can get to 500-600hp on a stock lower end without too much worry at all, although I might be looking for a stronger crank at that point, like from a 6.0L (which is cast, itself, not forged).
If I were keeping mine for towing duty, I'd probably look at a turbo; they do better in higher altitudes / thinner air than blowers do (one reason why Ford's EcoBoost motors do so well towing-wise). I plan on towing heavier, and regularly over the next couple of years - so I bit the bullet and bought a 3/4 ton w/ the 6.0L, and am giving it (most of) the same 'honey & nightshade' treatment that the Voy got. LOL
I absolutely love my Voy; she does everything I ask, within reason. And I DID get up the mountains - just a bit slower than everyone else. She does drink a little oil when towing (and I have a leak that I gave up trying to find), and towing that weight for hours on end does stress her a bit (I had to retighten my thermostat housing bolts). But she has never stranded me in 3 years of ownership.
Besides the oil issue (LS engines aren't exactly known for stellar oil control, either), it's a bit tighter in the engine bay; that 5.3L is really shoehorned in, compared to, say a full-sized pickup w/ the same engine.
Any other questions, just ask. Where in Canada do you live / plan to tow? (Americans don't bother with the metric system...that was a sure tip off that you were north of the 49th...
)