I wonder those who bought one if they are happy with the vehicle, and if anyone really tried to get the best tank with it. I heard slapping it in N forces auto stop but you can still coast, if that’s the case I don’t understand how you can take advantage of physics and get kick ass mileage! THAT”S BIG TO BOOT!

The Sequoia is only $4K more than our Yukon Hybrid as tested, not $15K, and that was the most expensive model. Add in a few more options on the Yukon, and they reach parity, yet the Sequoia has more “toys” (disregarding the very good hybrid powertrain). Factoring in base prices, the Sequoia and Yukon (non-hybrid) are almost the same.

And there are many vehicles competitive with the Yukon Hybrids. If you want the space and towing capactiy, get an Audi Q7. Want more luxury for the same price, get a BMW X5. Want a hybrid thats built better and gets fantastic mileage, while still having about 70% of the space, get a Lexus RX400h.

The Yukon is a good car, not a great car. But GM should not have passed on the development cost of the hybrid powertrain onto the consumer. That puts the build quality of the Yukon in a realm it cannot compete in, and a demographic that doesn’t care that much about gas prices other than a warm, fuzzy feeling that they are “saving the planet”.

hear hear! but it seems as if the automakers have no room for the station wagon anymore. mazda scrapped its pleasing 6 wagon, ford chucked the focus and taurus wagons. there are a few wagons remaining – the saabs, the volvos, the audis – but few can be had for below $35k.

the trend definitely is to phase out the wagon in favor of the SUV or the odd-looking and hardly more fuel efficient “car-UV,” though with current and forecast fuel prices, i bet both consumers and the manufacturers will regret leaving the wagon behind. instead consumers are faced with monstrosities like this yukon abomination.

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# Detroit-Iron :
February 27th, 2008 at 10:28 am

Why are American men and women so afraid of station wagons? I had a Focus wagon that was bigger inside than a Cherokee, and got over 30 mpg highway.

“To my knowledge, the 5.3L V8 in the trucks doesn’t use variable displacement, but the 5.3L V8 in the cars (Impala SS, Grand Prix GXP, LaCrosse Super) does have this system, so although it’s applied differently, GM has already implemented this system on smaller V8s.”

It’s been covered in the comments already, but, yes, the 5.3L V8 in GM trucks has cylinder deactivation. They first had it in August 2004 on the 2005 GMC Envoy and Chevrolet Trailblazer extended wheelbase models with the V8.

Ideally, if they can get cylinder deactivation working on their 6.0, roll it down to the other motors. Ditto the late-closing valves (if I’m right about that; it is definitely a trick Toyota is using).

To my knowledge, the 5.3L V8 in the trucks doesn’t use variable displacement, but the 5.3L V8 in the cars (Impala SS, Grand Prix GXP, LaCrosse Super) does have this system, so although it’s applied differently, GM has already implemented this system on smaller V8s.

The reason nobody buys diesel SUVS or standard sized pickup trucks is because they are not available, yet.

I don’t know about that. I had my folks pick up a CRD Liberty Diesel which gets 26mpg on the highway and was the best SUV value of the past 10 years. You got the Venturini italian built 2.8 CRD with a variable geometry turbocharger and the Ram’s 5 speed “Orion” transmission for only $1200 more. Daimler-Chrysler blew it when they moved the CRD to a V6 in the $42k Cherokee then didn’t offer it in any of the more affordable trim levels.

The Cummins Turbo Diesel with only a 4 speed auto vs 5 speed Orion in my Hemi Ram was an over $5000 upgrade. Not worth it to me as I still got the Heavy Duty frame, Dana rear end, 14 inch 4 wheel disc brakes etc. Plus just the Cummins is over 800lbs heavier than the Hemi.

Flat out wrong. Yukon Hybrid trailering capacity is 6,000 lbs period. Combined weight rating is 12,000 lbs.

Note the way GM calculates towing capacity: it includes all passengers and cargo inside the vehicle. So, if you have 1000 lbs of passengers and cargo the towing capacity is really only 5000 lbs.

Whoever gave you that information is incorrect.

The figure you want to look at then is the Gross Combined Weight Rating (GCWR) which is gross vehicle weight rating (GVWR) + maximum towing capacity.

For a Tahoe, the GCWR 13,700 lbs. With a curb weight of 5835 lbs, a GVWR of 7700 lbs, that leaves and additional 7783 lbs remaining for available towing. That means, even with a maxed out trailer, it’s still rated to carry over 1500 lbs of passengers and cargo. Somebody correct me if my math is wrong.

Towing capacity is not compromised by extra cargo.

The reason nobody buys diesel SUVS or standard sized pickup trucks is because they are not available, yet.

Aluminum Block engines are a little noisy. I noticed that with my 4B11 engine. It is light weight but with a little noise in the cabin. especially for the driver.

Probably it’s so light weight that the noise coming from the piston can be heard.

I’m just wondering with the V8 Aluminum block it might be louder than the original big block engine.

Note the way GM calculates towing capacity: it includes all passengers and cargo inside the vehicle. So, if you have 1000 lbs of passengers and cargo the towing capacity is really only 5000 lbs.

That’s the same towing capacity as a Toyota Highlander CUV, which is listed as 5000 lbs, excluding passengers and cargo.

So, this large hybrid has the towing capacity of a mid-sized SUV, less seating comfort and interior space than a minivan, uses a lot more fuel than other hybrids and is very expensive without being a luxury vehicle.
Is that supposed to turn on a lot of soccer moms?

The hybrid technology by itself is no magic bullet and was never intended nor expected to get leaps of gas mileage all by itself. That the Prius gets such high (cough, EPA numbers) is a combination of the hybrid drive, the hard skinny tires, electric power steering, goofy styling but ultra-slippery aerodynamics, the hot water bottle engine preheater, and driving it in low-intensity stop-and-go where the hybrid drive is optimized. When my brother in Florida bombs along at 80-per with the rest of the traffic to take the kids and mother-in-law to Orlando, he gets pretty much the same mileage as I get out of the old Camry he sold me when I drive legal speeds under the watchful eyes of the Wisconsin State Patrol, making sure those Illinois people don’t get ideas.

A Corolla gets x-MPG and a Prius gets x-MPG plus some increment epsilon (sorry, math talk). A Yukon gets Y-MPG and a Yukon hybrid gets Y-MPG plus epsilon. I guess we can argue until the cows come home (Wisconsin talk) about whether a Yukon is a vehicle anyone would want to drive or whether everyone in the market for one should downsize into an Acadia (or even a Prius for that matters).

But whether an SUV Yukon makes any sense to anybody given that there is the the CUV Acadia is a completely different issue than the hybrid drive. Maybe the issue everyone is getting at is that if you gorge yourself on a high-calorie “King’s cut” prime rib dinner, saving calories by getting the low-cal ice-milk dessert is a false economy.

“Awsome post phil! I completely agree about the hp/L arguments, its a ricer argument for those tuner boys that dont know much about engine physics and such.

The reason that smaller v6’s and 4cyl make good power for their size is

1:Good flowing cylinder heads using DOHC design.
2:High revving rpms with the smaller displacement.

GM could also use the DOHC design and get much higher output from their v8’s. Problem is, the engine will be much bigger and heavier than a smaller, lighter, and more compact pushrod v8.”

The weight difference between the iron and aluminum blocks (5.3L) is 60lbs (according to the GM Performance website), which is quite significant. The 6.0L weighs only 22lbs less than the 5.3L. I can’t find the corresponding transmission weight differences. A OHV compared to a OHC is about 100lbs (in favor of the OHV, Vortec vs Triton)

I have driven a Gen-1 5.7L in a GMC Sierra, and really liked it, and was even more impressed in the GTO application. I like the 6.0L even more, and the 6.2L makes angels descend from heaven.

However, if you’re only aim is economy, the 5.7L with Gen IV technology should have been the engine to use. It has a better reliability history than the 5.3L (opinion only, but the 5.7’s used by Occidental Petroleum in the Permian Basin lasted much longer than the 5.3’s), and with the Corvette flywheel and transmission components (from the C5), it would have a much better time coping with the hybrid drivetrain, and the off-on-off-on city driving.

GM currently doesn’t offer the aluminum 5.3L in the Yukon or Tahoe, they only offer it in the Suburban/Yukon XL (only talking SUV’s). I have no idea why.

And all the Vortec’s really are ancient designs. OHV in the 21st century? Come on! The only reason I see staying with a push-rod would be towing and low-end torque, but Ford has proven this wrong with their OHC Tritons. The 5.7 is less ancient than the 5.3 in that it incorporated a modern intake design, advanced combustion chambers, and several other goodies.

As for the torque vs. reciprocating mass argument, the 4-cylinder was an extreme argument, so lets use a scenario I’m very familiar with.

The previous gen BMW M-3 used a straight-6 design. It was well known for its free revving nature. The current gen-M3 uses a V-8. The cars are within a couple hundred pounds of each other, with horsepower differences of 60bhp (approximately). A different application than small-block V8’s I know, but bear with me.

Even with the power advantage, BMW had to significantly lighten the S65 V-8 engine components to maintain the signature M3 feel, a free-revving, high rpm autobahn burner. Even though the v-8 had a lot more torque, and just as much weight to pull around, the V-8 just simply didn’t sing like the straight-6, so they lightened the pistons, crankshaft, and adjusted the VANOS to compensate.

All things being equal (including horsepower), the larger the displacement, the harder it is to rev, simple physics of mass. The only way correct the problem is a lot more horsepower (and not just 10 or 20bhp), whether forced induction, variable intake/exhaust, or the tooth fairy. So if you don’t want to drastically increase the power (and reduce your mpg’s), you go with a slightly smaller, more rev happy engine, a la 5.7 vs 6.0.

Opinions really, but I could argue cars all day (and all night apparently), which is why I love TTAC. Where else can you argue semantics with the authors? C&D would laugh at you!

The higher displacement of the 6.0L engine would allow it to stay in 4 cylinder mode longer than the 5.3L engine. It would have more torque, when the 5.3L “runs out” of power, the 6.0 has more in reserve. This may actually allow it to be MORE fuel efficient than the 5.3L engine – only GM’s engineers know for sure.

But I’m sure towing capacity was considered as well. People buying this vehicle aren’t interested in compromising their vehicle’s capability just to get better fuel economy. They still need to tow boats, campers, trailers, etc.

Also, to respond to your previous comment, the FWD version of the 5.3L engine is very similar to the truck version. A few changes to the water pump/etc to allow it to fit between the fenders were necessary, but the internals are the same. Note the FWD engine has cylinder deactivation as well.

1. You say the 5.3L iron block is is heavy and ancient. Yes, it is heavier than an aluminum block. But there are versions of aluminum 5.3L that GM makes, and puts in trucks (even in the Yukon!). Also, I’d be interested to see the weight comparison between an iron block pushrod engine and a DOHC aluminum engine. Those three extra cams and larger heads add alot of additional weight.
As far as the 5.3L being “ancient” – you seem to imply that the 5.7L is superior, and GM should use the 5.7L, but add cylinder deactivation. The 5.7L is a “Gen3″, whereas the 5.3L in the Yukon is a “Gen4″. I am familiar with both of these engines, and there are not very many major differences between them – both are OHV, pushrod, etc. It was an incremental upgrade (Gen 4 essentially added cylinder deactivation, changed the cam sensor from the rear to the front, etc). Therefore I don’t quite understand your reasoning. Maybe I’m reading too much into your love of the 5.7L?

How can you compare a 5.7L engine in a car, to a 5.3L engine in a truck? The weights are vastly different. An engine with the same power/torque in both a car and truck will feel much more powerful in the car, as it is lighter.

And your comment: “If higher displacement meant an easier time reaching higher revolutions, then 4-cylinders should have a much harder time reaching the 5500rpm’s the V-8’s usually redline at” – If you were to put a 4 cylinder in a truck, I can assure you it would have difficulty reaching the 5500 redline you mention. As the engine speed is related to vehicle speed (through the transmission), the faster you can propel the vehicle, the faster the engine rev’s will rise. More torque will make the vehicle go faster, and therefore the engine’s rev’s will rise more quickly. If you were to do a drag race between a 5.3L and a 6.0L GM truck, the 6.0L would “rev faster” as well as win the drag race.

I am probably babbling at this point, but I think you get my point. Compare engines between vehicles of similar mass. It is difficult to compare a 4 cyl Subaru WRX engine to a V8 corvette engine to a V8 truck engine. Different Hp/weight ratios, etc.

Very plausible point. My side of it was, since it’d turn off 4 cylinders, the others would have to work harder thus burn more gas to turn the dead mass in the other half of the engine. The extra displacement of the 6.0 would help alot in that department, it wouldn’t have to work as hard as the 5.3.

First, there are lots of other SUVs that get 20 mpg, and most have some or all of the traits in this vehicle. You have the RAV4, which has three-row seating, a lower price, better reliability, and probably more offroad ability simply because it’s smaller and easier to maneuver, as just one example.

The second reason I don’t like this is because it calls GM’s attention away from its terrible small trucks and SUVs like the Chevy Colorado and Equinox. As long as these little trucks get the same fuel economy as the other trucks in their class, there’s little reason for them to exist, since the others are so much better in nearly all regards. This technology would help, but I don’t know if GM is putting enough effort into getting those vehicles more fuel-efficient powertrains. The fact that they’re putting so much into this while Colorados still do without V-8s or even V-6s makes me doubt that they’re even considering a hybrid (or much of an update) for either the Colorado or the Equinox.

I suppose the question is, why did they bother with this while their other vehicles are struggling so badly? Green cred aside, what’s the point?

Your research is correct. GM currently offers 4 versions of the current 5.3L, two iron-blocks, and two aluminum. And I believe GM used the 6.0L to offer more towing capacity, not to keep in 4-cylinder mode more often, but I’m not a GM engineer/head honcho, so only they know for sure.

Here’s the breakdown of the GM 5.3L offerings:

At present, four versions of the 5300 are in production: 2 iron block versions (LY5 and LMG) and 2 aluminum block versions (LH6 and LC9). All versions feature the Active Fuel Management system.

The LH6 (Aluminum) with Active Fuel Management replaced the LM4 for 2005, and was the first of the Generation IV small block V8 truck engines to go into production. It is the aluminum block counterpart to the LY5.

LH6 applications:
2005-2007 Chevrolet TrailBlazer including EXT
2005 GMC Envoy XL
2005 GMC Envoy XUV
2005-2007 Buick Rainier
2005-present Saab 9-7X
2007 Chevrolet Silverado 1500
2007 GMC Sierra 1500

Introduced in 2007, the LY5 (iron-block) Vortec 5300 is the replacement for the LM7 Generation III engine. For SUV applications, it is rated at 320 hp (239 kW) and 340 ft·lb (461 N·m) of torque; for pickup truck applications, it is rated at 315 hp (235 kW) and 338 ft·lb (458 N·m) of torque.

LY5 applications:
2007-present Chevrolet Avalanche
2007-present Chevrolet Silverado 1500
2007-present Chevrolet Suburban 1/2 ton
2007-present Chevrolet Tahoe
2007-present GMC Sierra 1500
2007-present GMC Yukon
2007-present GMC Yukon XL 1/2 ton

The LMG (iron-block) Vortec 5300 is the FlexFuel version of the LY5. Horsepower and torque ratings for SUV and pickup truck applications are the same as each application’s LY5 rating.

LMG applications:
2007-present Chevrolet Avalanche
2007-present Chevrolet Silverado 1500
2007-present Chevrolet Suburban 1/2 ton
2007-present Chevrolet Tahoe
2007-present GMC Sierra 1500
2007-present GMC Yukon
2007-present GMC Yukon XL 1/2 ton

The LC9 (Aluminum) Vortec 5300 is the FlexFuel version of the LH6, and is found in 4WD models. SUV applications are rated at 310 hp (231 kW) and 335 ft·lb (454 N·m) of torque.

LC9 applications:
2007-present Chevrolet Avalanche
2007-present Chevrolet Silverado 1500
2007-present Chevrolet Suburban 1/2 ton
2007-present GMC Sierra 1500
2007-present GMC Yukon XL 1/2 ton