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-   -   Report on Chevy/GMC 1500 with 6.2 engine and Max tow pack (https://www.airforums.com/forums/f463/report-on-chevy-gmc-1500-with-6-2-engine-and-max-tow-pack-137859.html)

DC Bruce 07-08-2015 12:23 PM

Report on Chevy/GMC 1500 with 6.2 engine and Max tow pack
 
After nearly a year of looking I found and bought a GMC Sierra 1500 SLT crew cab with the hard to find 420 hp 6.2 liter engine and Max tow package. This is a report on using it to pull my Flying Cloud 27, with a Pro Pride hitch. This truck, per the door sticker, has a rated cargo capacity of 1960 lbs. In my shopping, I was not able to find a 1/2 ton crew cab --other than this -- with more than 1730 lbs. capacity per the door sticker. The new F-150 promises over 2,000 lbs. with the max payload package, but that sticks you with the standard 20 gallon fuel tank (!) and Ford isn't making these until the fall. I've taken this combination through some of the Appalachians and on Skyline Drive/Blue Ridge Parkway. Respecting the limits of the OEM Goodyear Marathon tires on the trailer, I drive at 60 or the posted limit, whichever is lower (or as, in my judgment, conditions require). The engine easily pulled the grades I encountered, never going much over 3,000 rpm. I got 12-13 mpg on this part of the trip. The 8-speed transmission will downshift automatically to provide engine braking, even without engaging the cruise control (which down shifts more aggressively). Or you can change to manual mode and control the transmission yourself. Either way, the shifts are smooth and gentle. Most of the grades I encountered were curvy, so I was usually descending somewhat slower than the posted limit, and I slowed the rig to the posted "maximum safe speed" before entering a curve. This felt completely comfortable and drama-free. I used the brakes on descents, but never got them hot enough to smell. We were carrying a total of about 470 lbs of passengers (human and canine) and a modest amount of stuff in the bed (no generators). Other than the high price of required premium gasoline (usually 10-15 cents more than diesel), I have no complaints about the drivetrain; and observed fuel economy was 2-3 more mpg than I expected. This engine has variable displacement, and is very quick to shift to 4-cyl. mode. The suspension is a little underdamped, something that is apparent even when the truck is empty. An insufficient tension on the WD bars can produce an excessively bouncy ride on some roads; adjustment clears this up almost completely. So, if you are like my wife and I and are not thrilled with driving around a 3/4 ton (and you definitely feel the 1500-2000 lbs. additional weight driving these trucks) I think this truck is a good 1/2 ton alternative that provides a substantial cargo capacity almost equal to a lot of 3/4 tons, at least for use east of the Rockies. You will just have to look really hard to find it. Without the max tow package, this truck will have a cargo capacity of around 1500 lbs. This truck has extendable trailer tow mirrors and integrated trailer brake controller. The Max tow package includes a different rear axle and spring set up. I think the tow rating is something like 11,000 lbs. I think if I had a 30-foot trailer, I'd go for the 3/4 ton with a diesel. IIRC, the GVWR for the 30 Classic is 10,000 lbs. vs. 7600 lbs. for my trailer.

Mikem1961 07-08-2015 12:39 PM

I have a 2014 GMC with the Max Trailering package. Last year we used it to trailer, our then, 2000 - 30' Excella from Delaware to Key West and back and then to Maine and back. It has a 5.3 Liter engine and I had no problem. Everything went well and it only needs Regular gas. According to the trip computer we got an average of 10.8 mpg. I previously had a 2009 GMC 1500 with the 5.3 engine and there is a noticeable difference between the two when towing. Now we have a 2015 - 28' Serenity and I'm looking for a little better fuel economy.

KJRitchie 07-08-2015 01:18 PM

That is indeed a rare find. 2015 F150 has been a disappointment in the payload department. Max Payloads only have 20 gal, big disappointment. Guess the best payload with reasonable features you can find on the lot is the Supercab/XLT with 6 1/2ft bed with tow package. You'll have to spring extra for towing mirrors as none of them are coming with them in my area. Don't like the suicide doors on the Supercab. Guess my Tundra is safe for awhile.

Glad to read you are having a positive experience.

Kelvin

dznf0g 07-08-2015 01:28 PM

I just finished a 4500 mile trip with the 6.2l, 8-speed and 3.42 gear, NON-maxtow SLT GMC. I have a 30' Classic and wouldn't hesitate to get a maxtow with this setup, unless you have a lot of weight in the bed. For this trip I had little in the bed and I was below all GV specs, and GCWR.

I echo all Bruce says, except for the 30' "caution", if you will.

Overall MPGs 11.1 - 11.5 with a high tank at 12.6 and a low tank at 10.5.

VERY nice powertrain. I would like to see a payload rating bumped to 2400#s in a loaded truck though. If that were to happen, I would not consider a 2500HD.

KJRitchie 07-08-2015 02:07 PM

Do these 6.2L versions come with 30+ gallon fuel tanks?

Seems like most manufacturers are building their 1/2 tons to tow smaller conventional RV or utility trailers that aren't as heavy or have the tongue weight as most Airstreams 25 and above. They figure anyone towing heavier trailers/5th wheels will go 3/4t or 1t diesel.

Kelvin

dznf0g 07-08-2015 02:09 PM

Quote:

Originally Posted by KJRitchie (Post 1648643)
Do these 6.2L versions come with 30+ gallon fuel tanks?

Seems like most manufacturers are building their 1/2 tons to tow smaller conventional RV or utility trailers that aren't as heavy or have the tongue weight as most Airstreams 25 and above. They figure anyone towing heavier trailers/5th wheels will go 3/4t or 1t diesel.

Kelvin

27 gal on double and crew cabs. Might be 31 on a reg cab, but who wants that?

dznf0g 07-08-2015 02:11 PM

It's a space thing mostly. Lots of room under a long bed. Cab walls and floor is lower and prohibits tanks extending to under them.

Echelon73 07-08-2015 02:47 PM

I can believe the 6.2L with the eight speed transmission is great tow vehicle. I have a 2007 with the "VortecMax" package, which was 6.0L and the predecessor to the 6.2L they have now. Even back in 2007 when this was a 6.0L engine it had much more power than the 6.0L they use in the 2500 gas powered trucks. Mine even has the older 4L65E transmission which is terrible compared to these newer transmissions and still has plenty of power to tow our Flying Cloud 30. This new 6.2L / 8 speed / max tow and payload would be my ultimate tow vehicle (if I had $50K laying around).

phbarnhart 07-08-2015 02:57 PM

Quote:

Originally Posted by dznf0g (Post 1648627)
I just finished a 4500 mile trip with the 6.2l, 8-speed and 3.42 gear, NON-maxtow SLT GMC. I have a 30' Classic and wouldn't hesitate to get a maxtow with this setup, unless you have a lot of weight in the bed. For this trip I had little in the bed and I was below all GV specs, and GCWR.

I echo all Bruce says, except for the 30' "caution", if you will.

Overall MPGs 11.1 - 11.5 with a high tank at 12.6 and a low tank at 10.5.

VERY nice powertrain. I would like to see a payload rating bumped to 2400#s in a loaded truck though. If that were to happen, I would not consider a 2500HD.

I thought the 8-speed non-max tow came with 3.23 gearing while the max-tow got the 3.42. Am I incorrect? It was the older, 6-speed version that had 3.42 on the regular and 3.73 on the max tow?

phbarnhart 07-08-2015 02:58 PM

Bruce - Thanks for the update! I'm glad you were able to finally find your unicorn and that it's worked out for you!

ghaynes755 07-08-2015 03:41 PM

Buce have you taken it over the CAT scales when fully setup for camping? Would be interested in the Front/Rear axle weights.

dznf0g 07-08-2015 03:49 PM

Quote:

Originally Posted by Echelon73 (Post 1648663)
I can believe the 6.2L with the eight speed transmission is great tow vehicle. I have a 2007 with the "VortecMax" package, which was 6.0L and the predecessor to the 6.2L they have now. Even back in 2007 when this was a 6.0L engine it had much more power than the 6.0L they use in the 2500 gas powered trucks. Mine even has the older 4L65E transmission which is terrible compared to these newer transmissions and still has plenty of power to tow our Flying Cloud 30. This new 6.2L / 8 speed / max tow and payload would be my ultimate tow vehicle (if I had $50K laying around).

The 6.0 and 6.2 are in no way related. Completely different engine family. The truck 6.2 is akin to the Camaro and Vette engines with different heads, intake, crank, rods, etc. 6.0 is a cast iron block and the 6.2 is an aluminum block.

6.0 is still used in HDs as it's 4 bolt main and cast iron is needed for gut wrenching construction hauling and loaded off roading at construction sites, etc.

dznf0g 07-08-2015 03:52 PM

Quote:

Originally Posted by phbarnhart (Post 1648670)
I thought the 8-speed non-max tow came with 3.23 gearing while the max-tow got the 3.42. Am I incorrect? It was the older, 6-speed version that had 3.42 on the regular and 3.73 on the max tow?

You are correct....still had my head wrapped around the 6 speed combos.

Echelon73 07-08-2015 04:43 PM

Quote:

Originally Posted by dznf0g (Post 1648699)
The 6.0 and 6.2 are in no way related. Completely different engine family. The truck 6.2 is akin to the Camaro and Vette engines with different heads, intake, crank, rods, etc. 6.0 is a cast iron block and the 6.2 is an aluminum block.

6.0 is still used in HDs as it's 4 bolt main and cast iron is needed for gut wrenching construction hauling and loaded off roading at construction sites, etc.


I think you are referring to the "LQ9" which they use in the 3/4 ton HD trucks. Mine has the aluminum "L76" which I believe came from the Australian Holden lineup. They only offered it from 2007-2009 in the 1/2 ton trucks. It was then replaced with the 6.2L in 2010. It is a completely different engine than what is in the 3/4 trucks though.

dznf0g 07-08-2015 05:05 PM

Quote:

Originally Posted by Echelon73 (Post 1648717)
I think you are referring to the "LQ9" which they use in the 3/4 ton HD trucks. Mine has the aluminum "L76" which I believe came from the Australian Holden lineup. They only offered it from 2007-2009 in the 1/2 ton trucks. It was then replaced with the 6.2L in 2010. It is a completely different engine than what is in the 3/4 trucks though.


Yes that is all true, and I re-read your post and thought that was what you meant, but I believe that the holden 6.0 (Also used in the SSR, I THINK), is not really related to the current 6.2. I believe it is a completely different casting and shares few if any parts with the current 6.2 in cars, and even less with 6.2 truck motors. In fact, the Gen3 Vortec family shares little with the Gen2 Vortecs. I may be wrong here, as I don't focus much on non-fleet type vehicles, but I think the old L76 was only in high performance trucks like SS in that 2007 - 2009 time frame. Also, IIRC high end Cad and GMC SUVs.

Echelon73 07-08-2015 06:33 PM

Either way, I agree that a 1500 truck with a larger V8, proper gearing, and heavier payload can actually make a great tow vehicle for even the larger Airstreams.

SSquared 07-08-2015 10:33 PM

DC Bruce, I believe the Sierra 1500 crew cab can come with either of two different bed sizes. How long is your bed?

DC Bruce 07-09-2015 10:38 AM

I have the short box, which, if memory serves, is 5'8". Less room for stuff=less opportunity to overload. 😅 I also have a lightweight bed cover, which is sufficient to keep the rain out. Interestingly, all of the 6.2/max tow combinations I found were short box. Don't know why this is, because the combination theoretically is available with the long box. Rear axle ratio is 3:42, which works because of the lower first gear in the 8-speed tranny, as compared to the 6-speed. IMHO, having driven both transmissions with this engine, the 8-speed is definitely worth having. The ratios of the 6-speed are just awkward. Also, having driven both V-8s with the 6-speed, the 6.2 engine is definitely worth it, if you can tolerate the more expensive fuel. The 5.3 feels weaker than it really is; you feel like you're flogging it to get it to accelerate at more than a leisurely pace. Also, N.B. the 8-speed comes only with the big engine. That may change in the future, and the 5.3 with the 8-speed might be a whole different animal than it is with the 6-speed. I will say in normal driving, the 6.2 doesn't feel any quicker than the '14 or '15 3.5 Ecoboost even though it is substantially more powerful and has somewhat more torque. However, like all turbocharged engines, the Ecoboost has a somewhat non-linear throttle response. I suspect the V-8 might get a little better fuel economy, especially towing. Turbocharged engines run rich under boost to cool the combustion chamber to avoid pre-ignition and other nasty situations.

Maineiac 07-09-2015 12:12 PM

If you have ridden in both? How would you describe the ride compared to the 1500 without max tow when not towing anything? I had heard one owner describe it has half way between the 1500 and 2500? Somewhat stiffer?Also is the premium fuel mandatory or optional on 6.2. Howard

phbarnhart 07-09-2015 12:16 PM

91 octane is recommended and some of the owners at the tahoeyukon forum have noted some knock when running regular fuel. Frankly, it's just not worth it, IMO to put regular gas in it, it's not THAT much more expensive.


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