Mileage Dropoff

gcope63 · November 15, 2003

I am looking to order me a new Silverado in a couple of months and am still trying to decide on the motor.. I will be hauling a 3000# Camper and pulling a 5000# boat and wanted to know how much of a difference in mileage people have been seeing with their Duramax towing loads of approx this much?? I have a friend with a 2003 Duramax and he is getting around 20 mpg empty but has not towed anything with it.. I know the 8.1 would be considerably less but how low do you think it would go?? Right now just pulling the boat with our Yukon we are only getting around 9 mpg, I suspect the 8.1 with the camper and boat would be around that range..

Thanks in advance!!!

Gary

c5hd · November 15, 2003

I am getting 23.6 MPG uloaded, 18 MPG towing 7500 lb.

BlackSilver · November 15, 2003

I am getting 23.6 MPG uloaded, 18 MPG towing 7500 lb.

You must drive downhill with a tailwind a lot, or your mileage calculator is very generous!

My Duramax/Allison 2WD Ex Cab runs about 21MPG (Highway) empty.

When pulling my boat (1500#) it runs around 18MPG.

When pulling my 5th wheel (7800#) it runs around 14MPG.

When pulling both (9300#) it runs around 13MPG.

Those are mainly "flatland" miles in the summer. In the mountains it'll drop off some, and when you run winter blend fuel you will also see some decrease in mileage.

Shaners · November 16, 2003

The 8.1L gasser will probably yield upper single digit MPG's when towing.

With the weights that you have the 6.0L would do a fine job, and would save you about 3 grand over the bigblock/allison combo.

I get around 8-9 MPG's towing my 8500 lb 32' travel trailer with my 6.0L. I run 60 uphill and 70 downhill and don't use the cruise. I have to rev the motor more than you would if you had the 8.1L, but I doubt I'm hurting it....

Wingnut · November 16, 2003

I'm with Shaners.....Get the 6 liter.

He!!, you can tow that stuff with the 5.3.

I do.

MCourson · November 16, 2003

The 03 here gets 21 empty, and 13 towing 10,000lbs

RonJ · November 16, 2003

Hey, Blacksilver;

Do you have a picture of your duramax towing the 5th wheel & boat at the same time? I don't believe I've seen that done before. I've seen tractors pull twin trailers, but no campers and boats.

MCourson · November 16, 2003

I have seen it done but not often.

422 SS · November 16, 2003

Hey, Blacksilver;
Do you have a picture of your duramax towing the 5th wheel & boat at the same time? I don't believe I've seen that done before. I've seen tractors pull twin trailers, but no campers and boats.

I have seen it before but it's illegal in most states.With the small load you will be pulling I doubt you even need a HD.A 5.3 1500 would do the job you describe.

BlackSilver · November 16, 2003

Hey, Blacksilver;
Do you have a picture of your duramax towing the 5th wheel & boat at the same time? I don't believe I've seen that done before. I've seen tractors pull twin trailers, but no campers and boats.

I don't have a picture, but it's legal in many (most?) states.

Here in MN the rules require the RV be a 5th wheel rig no longer than 28 feet, and the second trailer must carry a "recreational" toy (boat, 4-wheeler, PWC, motorcycle). It's quite commonly seen here during the summer.

THE BIGPUNN · November 16, 2003

ronj, i have seen a lot of people tow boats and utility trailers behind their campers. the main thing is to stay at speed or below. this past summer i was passed on the highway by a guy in a 3/4 ton dura ext cab.. he had plenty of power obviously, but his boat and 5er was swaying all over the highway, i slowed way down because i thought this idiot was going to lose it! i am considering adding a hitch to my tt bumper to tow my light aluminum boat about 20miles to my favorite campground to fish, havent made my mind up for sure.

gcope, i agree a 5.3 or 6l would do you fine. think about the future though, if your gonna upgrade you might as well get the biggest you can afford now.

raventai · November 16, 2003

the 8.1 does not drop mileage much when towing

I have made a few runs to Tennesse with hauling a 4,000# Toyota truck (not a stock Toyota) and I actually got about 13 MPG mainly because the trailer was a POS and I could not go over 60 without vibration, I normally get between 10 and 12 emty depending on how much of that tank is around town and how heavy the foot is

gcope63 · November 16, 2003

WOW, thanks for all of the info!! I really don't think a 5.3 would work and i seriously don't think a 1500 would handle the 3000# camper

I was pretty much sold on getting the DMax but then I started seeing where the mileage drops off quite steeply when you start towing and was wondering how much of a difference there really would be between the two big motors towing my load... And I do like the sound of a BB engine

I am towing now with a '97 Yukon and it is all it can do to get just the boat over some of the mountains around here, so that is why I am looking at least the 8.1L.

Thanks

Gary

MCourson · November 16, 2003

I really don't think a 5.3 would work and i seriously don't think a 1500 would handle the 3000# camper

300lbs is no problem for a 5.3 or a half ton. I used to pull 5000lbs with a 2001 GMC Sterra 1500 with the 4.8.

gcope63 · November 16, 2003

Oh, also, I have seen a few of the double trailer loads, actaully thought about it myself for a bout .002 seconds They seem to be very sensative to any kind of crosswind such as when a semi cruises by and driving down the Columbia River Gorge would be great fun, constant strong winds.. Didn't want to have to worry about it so that is why I am going with the camper.. Plus my wife will be driving some of the time and she has a hard enough time with a boat, can't imagine her with two trailers behind

Another thing on the Diesel/Gas issue is my driving style, I usually do not drive slow, it actaully drives me crazy to have cars passing all of the time I am not talking 90 on the interstate but want a comfortable 70-75 on the interstate. I hear the diesels really drop off mileage wise when you are up in those speeds, any input on this??