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Davis · 06-18-2005, 07:09 AM

Hi all,
I am considering buying a New Suburban or Yukon XL 2500 while the GM discount program is being offered. I will be looking at one with the 6.0 engine, 3.73 rear axle ,and 2WD. I will be using this vehicle as a daily driver also. What fuel mileage could I expect solo and towing ? Also are the trailer towing mirrors worth the extra money or do they cause problems ? Thanks for the info. Davis

john hd · 06-18-2005, 07:24 AM

davis

just off the top of my head i would predict 15 to 17 normal driving, 13 to 15 towing. possibly higher due to the 2WD.

my silverado has the same engine but lower gears (4.10) and gets about this for m.p.g.

john

john hd · 06-18-2005, 07:27 AM

also,

i just saw your profile, you have a six wheeler! you may want to consider the 4.10 gears before you purchase!

john

Ken J · 06-18-2005, 07:32 AM

You also may want to consider the 8.1 liter engine for about the same gas mileage - I really love that motor in mine.

Ken J.

Davis · 06-18-2005, 07:55 AM

Thanks for the replies. But I also want to use this a daily driver 95% of the time and tow the other 5% . So I figured the 3.73 gear ratio would yield the best fuel mileage solo or would there be much difference ? Thanks Davis

Steve Heywood · 06-18-2005, 09:53 AM

Quote:

Originally Posted by Davis

Hi all,
I am considering buying a New Suburban or Yukon XL 2500 while the GM discount program is being offered. I will be looking at one with the 6.0 engine, 3.73 rear axle ,and 2WD. I will be using this vehicle as a daily driver also. What fuel mileage could I expect solo and towing ? Also are the trailer towing mirrors worth the extra money or do they cause problems ? Thanks for the info. Davis

Based on my experience with the LS1 based truck engines you'll be much better served with 4.10 gears, ESPECIALLY if you plan to tow a 34' A/S.

Foiled Again · 06-18-2005, 01:25 PM

I'm only pulling a 22ft CCD with my Suburban, but I added the electric towing mirrors and think they were well worth the money. When backing into a space, I can just turn the mirrors down and keep the water, sewer and electric hookups right in my sight line. Really easy to get everything lined up right.

If I park in a public lot, with a 22' I can almost always straddle two facing spaces as long as I get the hitch directly over the line, I use the mirrors to do that painlessly. Basically I adjust my mirrors every time I'm in a tight spot - like a gas station or pulling onto a major highway from a side road. I also never have to worry about them coming loose or going out of adjustment. KISS!

My mirrors pull out manually about 8 inches for towing, and theya re oversized compared to stock mirrors because they consist of a small convex mirror on the inside and a large, flat electrically adjustable mirror on the outside. Pushing them in when not towing is mandatory - especially if you EVER want to use a drive in window.

I added mine for slightly over $500 and they are worth every penny. You can spend even more and get the signal arrows built into the mirrors, but that just seemed dumb to me.

Tin Lizzie

zoom240 · 06-18-2005, 07:21 PM

Davis,

I just bought a 2500 Yukon XL with the 6L and 4:10 gears. I've got about 2000 miles on it & getting about 13.5 mpg. I did a lot of looking before I bought - you don't have as much GVWR with the 3.73 gears, so give it some thought about what you're towing.

The discounts are very good because they also take off the rebates.

You'll have a hell of a time finding one with the 8.1L engine. I had them search - there wasn't one within 800 miles from me (live near New Orleans). I did find one in Wyoming, but that's too far.

Dave

Over59 · 06-18-2005, 09:06 PM

Dura Max. Live Large.

Bradjun1 · 06-18-2005, 10:40 PM

Davis,
The 6.0 will pull your trailer just fine in most conditions. If you plan on mountain climbing the 8.1 will be better, but if you're like most of us mountains are a small part of the overall picture. The 3.73 will be more economical when used as an everyday driver. I have a friend with the same package and he reports 11-13 mpg towing a 8800# trailer and 17 mpg hwy. In most conditions you will want to lock out the overdrive. According to Chev specs the 3.73 will tow 7900# while the 4.10 will tow 9900#.

SilverToy · 06-19-2005, 12:49 AM

Bradjun1

Saw your post about 'Locking out the overdrive'....why? What does that do that when if i don't do causes problems? Is this for mountainous routes or the flat middlewest with wiht the 24 Hour MEGA Wal-Mar and Open24 Hours.

The answer is actually CRITICAL to me since I am leaving a 1400 miles oneway trip. The way back is still bit open.

The towing from our 7200ft elevation down to the flat land elevations in Tx, OK, and IL and IN tossed in for good refereance.

Does the OD shorten the life of the trans???IF so why? OR is it a rolling down the highway question. What exactly caused you to say that statement.

Again, not trying to be a ButtHead but am looking for real answers that could save my Tranny from heat, overuse and/or dreakdown on this ride....

Needing that help Airstream Family.

Thanks in advace for you help and opinions.

Axel

Ken J · 06-19-2005, 07:35 AM

Hello Axel.....

I was told by my transmission guy never to tow in overdrive unless its very flat - however as soon as it starts to hunt, take out of overdrive. He said that even thought the manual says you can tow in overdrive don't - he says all GM has to do is get the transmission past 36,000 miles after that it's not their problem. He showed me the cluches that are in that transmission - first gear is very large, overdrive is very small - he says you can burn up the clutch over time - he even suggested not using overdrive while not towing in the mountains. You may want to give them a call - its called CATS transmission in Farmington. I consider them to be pretty reliable and they are nice folks.

BTW - I have the 8.1 with 3.73 gears and I'm getting the same mileage as the 6.0 folks. Love that motor - its a rocket. Took a free (without trailer) the other day and got 18mpg.

3Ms75Argosy · 06-19-2005, 09:01 AM

something about the slippage that goes on in OD, heats up the tranny too hot. Trannys die with heat. I believe the 3rd gear is a direct lockup. I shift down to second when I hear it unlock on the hills.... course, this is for my Dodge Ram Van. It also says not to tow in OD in my manual.
Marc

zoom240 · 06-19-2005, 02:08 PM

I was towing a 28ft with a 1/2 ton Z71 & the 5.3L with 3.73 gears. Even on flat land, at highway speeds it would "hunt", ie., go from overdrive to 3rd & back again. All the shifting can't be good on the transmission. It may also be "slipping" the clutch to before it shifts, trying to maintain torque. Can't say really, but it did pop back & forth all the time. Even had tow mode on, which is supposed to keep it from shifting so frequently.

But, towed in 3rd gear no problems. Gas mileage was about 10 mpg. I had the tow package with transmission cooler though.

Dave

Bradjun1 · 06-19-2005, 07:59 PM

Axel,
On flat ground you can tow in OD with no problem. If you encounter hilly terrain and your transmission starts to hunt for gears or starts to shift to often you can lock out the OD. I also drive without the cruise control and back off the gas in hilly country and this will also prevent the transmission from shifting too much. The more it shifts the more the heat can build up hence shortening the tranny life. If you have a tow package and stay out of OD and adjust your speed to the the terrain you should be just fine.

SilverToy · 06-19-2005, 11:51 PM

OK, saw the answers on the OD vs. no-OD towing but still have a question or 2.

Pulled SilverToy home to ABQ from SLC over some REALLY mountainous terrain. As mentioned in the Title, I have the '01 2500 'Burb with the full heavy duty factory tow package - 39K on the odo. SilverToy is a '92 34' Classic Lmtd. This was the first heavy tow for the vehicle and for me. When we were going uphill (25+ miles) with lots of 10 or 12% grades I noticed some hunting - even with the Tow/Haul engaged. BTW - What does T/H do exactly?? Dropped to 3 several stretches (as oposed to D) to keep her in the power.

Anyway, going uphill the trans temp did rise to the nearly 200degree (according to the factory gauge - no calibrated sensor) and I kept a REAL close watch on it. Without a trailer it has never been over about 150 or so.

Also, coming up the mountain to our abode is about a 1 mile trip with the average grade at about 14% - when I get on that road the temps will again be about 200 when I get to the top and back the rig in the drive. Noticed some pretty intense tranny smell a few trips back but nothing over 200 on the gauge. So now the question - did I hurt it? SLC trip, local, in general?

Naturally the smell indicates that it is NOT loving these intense pulls but it should be OK long run, right?? Should I do a tranny service - what exactly? - or just leave it as the manual (100k service?) and do as the service computer in the truck tell me?

Just curious as I am leaving to pull SilverToy back east to Michigan in about 6 days and now I am thinking ..... I know, bad combination! Anyway, let me know what you gentlemen and women? think. Thanks!!

Axel

john hd · 06-20-2005, 05:39 AM

axel

if you read your trucks manual carefully you will see two schedules for maintinance.

you will see the under the severe duty schedule you should change it every 50,000 miles.

when you get to your destination it would be a good idea to let the truck idle until the temp drops below 150 before backing it in. pushing something as heavy as a 34 footer in reverse generates a lot of heat. that is very tough on a already hot tranny.

i did not notice if you have 4 wheel drive, if you do, consider putting it into low range before backing in. low puts a lot less stress on the drive train.

if you have smelled the "hot tranny" smell changing your atf now would not be a bad idea, i just had mine done at a chevy dealer, 100 bucks total. cheap insurance.

john

Silvertwinkie · 06-20-2005, 06:37 AM

I have the vehicle you are considering and the tow rating I am not sure will work with 3.73s. Matter of fact, even with the 4.10s you are only at about 9900lbs with 2WD and 9600 w/ 4WD tow capacity. With the 3.73s according to the Chevy website, it's rated at 7900 for the 2WD and 7600 for the 4WD.

http://www.chevrolet.com/suburban/sp...ns/#trailering

Now I just saw a new 34' tri-axle this weekend at the midwest rally, though it has the upgraded axles now, I am **positive** that the 34' units, even from 1991 still weigh more than 7900lbs and think they even weigh more than 9000lbs, so clearly the 8.1L might be your ONLY option if you stick with a Suburban. Fuel economy I seen between 10.7mpg and 12.9mpg towing with the 6.0L 2500 4x4 Suburban. Around town not towing the same truck gets about 10mpg. I haven't taken it on the highway not towing, so I don't have info on that yet.

The Yukon will have nearly identical performace as the Chevy, if not identical.

Ken J · 06-20-2005, 06:37 AM

I change my trans fluid once per year - each fall. I think its a good idea to keep watch on it, when they change it they can look at the color - smell it etc and tell if you have overheated it.

All the tow/haul does is increase the time it takes between shifts so the transmission does not have to hunt as much....

If I were you I would go ahead and have the trans fluid changed - if it looks burn't at all - even if it didn't with the load your pulling - I would put synthetic in - it tolerates heat much much better

Ken J.

Silvertwinkie · 06-20-2005, 06:42 AM

I agree SilverToy....change the fluid now. Also do you have 4.10s or 3.73s? If you have 3.73s, that might be your problem, plus to be honest, a 34' coach with the 6.0L, even with 4.10s might not be such a hot idea...no pun intended.

Also see that you collect pinball machines....me too...I'm an avid mid to late 80's through mid 90's Williams Pinhead!