first towing trip

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by XS ive, Jun 28, 2012.

  1. XS ive

    XS ive Rockstar 100 Posts

    Hey guys. Been a while since I posted, actually it was almost a year ago when I was looking for info. on an electrical gremlin. Gladly, said gremlin was evicted and my truck has been flawless since. :great:

    I purchased an enclosed trailer this spring to haul our MX bikes and gear around and have been making my garage queen work lately. Trailer is an 07 Roadmaster 7x12 v-nose tandem 7k man cave.

    We just did a 1297 mile round trip towing it full of bikes, gear, food, and beverages from eastern LI to Medina Ohio. It was hot with ambient temps near 90* both ways through the Poconos and Adirondacks on route 80.
    I would estimate max total GCVW was no more than 9500lbs. The truck pulled without problem between 60-70 mph with the trans. temps. on long up hill grades getting up to about 215* and the engine temp climbing to about 220*. Both seemed to head back to normal engine 210, trans around 200, shortly after the crest. I used tow haul most of the time just for piece of mind and it allowed the engine to purr at just over 2krpms in 4th/ OD, and when it kicked down to climb just about 2750 rpms. Overall mpg was 11.1. I was hoping for over 20 but.....
    This is the first experience with over the road towing with my truck. I didn't like the trans. and engine temps climbing, but I was pushing it up the grades.
    Does this sound normal to you guys?
    Thanks in advance,
  2. chevybulldog6

    chevybulldog6 Rockstar ROTM Winner 100 Posts

    The trans and engine temp slightly climbing while ascending hills does sound normal from my experience. However, the mpg sounds a little low to me. But what size tires are you running and have you re-geared the axles? If you are running stock gear ratio with a 6in lift and larger tires then the 11mpg might be all you will get. I have only done a little bit of towing with my 2005 but it sounds about the same. I pulled a 1987 K5 blazer on a car hauler 850 miles and averaged around 10-11mpg with my lift, 35s and factory gear ratio.
  3. XS ive

    XS ive Rockstar 100 Posts

    I am running the stock 3.73's and 35" tires. On a flatter road without the long grades I have pulled 12.9 towing the same weight. I am still kinda concerned about the trans temps though. While dealer and 50% of internet info says it's normal, some say over 200* is not acceptable. I may look into replacing the OEM cooler with something beefier.

    99'HEARTBEAT MODERATOR Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    In my Silverado Owners Manual, it expresses, the Normal Operation Transmission Temps are between 100 to 265 Degrees, when Towing my Boat, my Trans. Temps were between 180 to just over 200 Degrees, with the Factory Trans. Cooler, even tho these number were with-in the specs mentioned above,

    I was Still Not Comfortable with my Trans. running at these Temps, so I swapped out the Factory Trans. Cooler for a......Aftermarket True Cool 40K Transmission Cooler, and with this New Larger Aftermarket Cooler, when Towing my Boat, my Trans. Temp have Never gone over.....150 Degrees!!.....

    The Below link is from Mag-Hy-Tech, which makes, Aftermarket Trans. Pans and Diff. Cover, has a Chart showing Transmission Life Relative to Transmission Fluid Temps, and I have installed their Transmission Pan and Diff Cover......and IMO they are the Best Ones, on the Market, for the Money.

    Below is my thread, on Installing the Aftermarket True Cool 40K Transmission Cooler,

    Last edited: Jun 28, 2012
  5. chevybulldog6

    chevybulldog6 Rockstar ROTM Winner 100 Posts

    I would agree with replacing the cooler with a larger aftermarket model if you plan on doing a lot of hauling. I don't do that much so for me I feel the factory cooler is sufficient.
  6. bcms6

    bcms6 Member

    I get 10-11 MPG towing my 8K enclosed 8X24 flat nose trailer. GVW would be about 15K. That is all fwy with a couple short but steep grades mixed in. Truck is 2005 2500HD extended cab RWD gas. You have a lighter trailer, but more hills. Hills are brutal on fuel consumption, so your MPG may be reasonable.
  7. Sierraowner5.3

    Sierraowner5.3 Epic Member 5+ Years 1000 Posts

    i had over 5k behind my old 05 with the factory cooler. I did 1300 from minnesota to Virginia beach and averaged right at 11. factory tires and gears, no lift.
    i did have a 87 hypertech tune.

    this was with a 6x12 uhaul. dunno what i was getting for trans temps as i had no gauge, but engine temp never got over 220 ( late march) those hills are killer, trying to run 70 over em will kill your mileage. id hit the bottom at 65-70 and slowly drop on the way up till i hit 55-60 and hold it there.

    not a apples to apples comparison, but its close.

  8. XS ive

    XS ive Rockstar 100 Posts

    Thanks for replies guys. I may just think of a larger cooler for future upgrade. I like the way that True cool looks OEM, and the fact that it has a "thermostat" for the winter months.
    Yeah, the hills on I-80 in Pa. are kinda large and drawn out. Kinda like I-80 in Pa..... That road goes on forever!

    99'HEARTBEAT MODERATOR Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    Charlie, I don't know if you looked at the last page of my Thread(True Cool)??.....the reason I mentioned this, is that fellow Member Mfleetwood, who has an 08" Sierra, did the True Cool Swap on his just in case you were wondering if this Swap will Work/Fit on your Truck, like on my Truck, it does and has the same Factory/OEM look to it, when done with swap.
  10. XS ive

    XS ive Rockstar 100 Posts

    I did see your post. Very informative and a great job showing the steps. Thank You. That's what got me thinking of the TrueCool.
    I also found the link for the brackets to make it fit like OEM. I haven't researched, but I am thinking they will be the same ones needed for my 08.

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