Someone has questions about the Vortec 8100 engine? Why not ask the man who owns one?
😉
Five years ago, I bought a 2001 Suburban 2500 4x4 with the 8100, 4L80E and 4.10 gears... and 219,500 miles. I bought it solely to use as a tow rig. Before I actually went through with it, I admit I had two concerns: the high miles, and the low fuel economy. A Chevy-loving co-worker brought me around about the longevity of the engine; he pointed out how this was a very strong, overbuilt engine which was "designed to run at a constant 4000 rpm all day long" according to him. As I researched it, I saw how common this engine was in heavy-duty applications... and I quickly learned how respected it is. As for the economy, I asked all my Jeep buddies who also tow their rigs on open trailers. That's when I learned something funny. The Chevy guys point out that, when driving around without a trailer, the 5.3 V8 gets better mileage than the 6.0 V8, and the 6.0 V8 gets better mileage than the 8.1 big block. <duh> But when you put a more-or-less identical Jeep on a more-or-less identical trailer behind the truck, all three engines end up getting virtually the exact same mileage. The smaller engines have to work extra hard to tow the same load the big block can move without breaking a sweat. As soon as I heard that, I decided I would go with the powertrain that can most easily do the work I needed it to do.
Since buying it, I have put
thousands of miles on it with my car hauler hanging off the hitch. It now has over 254,000 miles. The item most frequently towed--and the primary reason I bought the thing--is my Jeep Wrangler. Here is an all-too-common sight, this photo taken in Moab at the end of last year's Easter Jeep Safari:
When towing my Jeep as shown above, the total combined weight of both vehicles/trailer/cargo is +/- 12,800 pounds. The engine handles this load very well (actually, the entire vehicle does a great job). On mild interstate grades, I can usually chug right up in overdrive at ~ 70 MPH and 2350 RPM. Steep hills will cause the transmission to downshift and unlock the converter, then after a few seconds the converter will usually re-lock and I'll cruise up the hill at 65 MPH in 3rd gear and 3000 rpm. While towing my Jeep, my calculated fuel economy will usually be around 10.5 mpg depending on exactly how fast I'm going (though I usually don't go over 70 MPH when I have a trailer attached).
Speaking of fuel economy, I did have a chance to compare mine with a smaller V8. Back in January, my friend Mike and I both towed our 454 cars down to Tucson for the Roadkill Zip-Tie Drags. I used my 8.1L Suburban, while he used his 5.3L Yukon XL. We were each towing identical loads, and we drove the same roads at the same speed there and back.
At every fuel stop, we would calculate and compare fuel economy. The biggest difference was our first stop--which was overall a gradual downhill drive--where he saw .5 mpg better than me. The rest of the time, the difference was even less... and on our first re-fill on the return trip (where there were numerous hills) I actually got better than him by a couple tenths. Any time we hit a hill his transmission would drop two gears and he's scream up it at 5000 RPM all the way, and that takes its toll on your fuel consumption.
I'm thinking of putting it in is a heavy work truck about 11000 lb with a th400 4;10 gears and 31" tires and needs to do 80 mph at times
My Suburban has 30.5" tires. With your slightly larger 31s and no overdrive, 80 MPH is gonna keep you spinning 3600 RPM or so. I don't think this will be any problem for a 8.1L engine--that engine speed is below the HP peak, after all--but having the overdrive would certainly make things more pleasant. Knowing the abundance of the 4L80E transmission, I'd suggest using one if you can rather than the TH400.
I don't trust a 4l80 or a 700r4
Wow, I don't know why you have trust issues with the 4L80E. When everybody says it's essentially a TH400 with an overdrive, they're correct. I certainly love mine. To each their own, I guess.
just like any other truck big block, they don't really like to rev.
They may not wanna scream down the highway at a constant 5000 RPM like my friend's 5.3L small block, but they don't need to. As I explained above, the big block can do at 3000 rpm what the small block has to turn 5000 RPM to accomplish.
And like
ssn696 said, super-thirsty.
Also addressed.
😉
