Increase power/torque for towing

Changing gears also raises RPM.
Which also adds heat and stress.
Not really a way around heat and stress when working an engine.

 

Ran 350 miles with the travel trailer from my home in the McKenzie Valley near Eugene, OR to Port Angeles, WA. All hills once we got out of Portland, and I averaged 7.8 MPG overall.

I maintained 65 on the interstate, and ran with traffic once we hit the smaller highways. Typically in the 60 mph range….

While I had zero trouble maintaining speed on the hills accelerating when I wanted, I wouldn’t be able to pass much if I wanted to pop out into the oncoming lane and get around a slow poke on a hill.

My thought here is that a supercharger is in no way needed for towing within our capacity, but it would certainly open up your options if you’d really like to beat feet.

Also worth noting, I never saw over 1,000 feet of elevation today. It was all little hills with dense air… I’ll get up into the 4,500’ plus range in a week, so we’ll see how that goes. I’ve done it before without issues though! It’s just not gonna keep up with a big diesel.

 

You can run larger tires and bring the RPMs down closer to stock range.

 

Quick comparison, my rpm at 60 mph with 34” tires and 5.29 gears is ~275 rpm higher than 32” stock tires and 4.30 stock gears. It’s not as big of a difference as a lot of folks think. I’d do 5.29s with any tire size over 33”…. Our trucks are geared too tall from the factory if you want much in the way of performance…

 

Or get gears AND a supercharger why not both

 

@dirtydeeds said as much regarding 5.29s and 33"+

I run 37s and hit 2100-2200 RPMs at 75 mph

 

Sounds just about spot-on with what I get with stock 32" at that speed. (4.30)

 

Gonna be pretty hard pressed to find a decent argument to this logic! I simply haven’t convinced myself to pull out my wallet yet!

 

Any updates on towing after getting higher elevation and vertical gain in one go?

i just bought a 2020 Limited to tow a 2024 Axis T235 boat. Boat dry weight is 5,200. I’m guessing the trailer isn’t more than 1,200. Add fuel and toys and it adds 500 lbs. In total weight is around 6,900 maybe 7,100 being conservative. I’m in Utah and towed on I-80 over Parley’s canyon (summit is 7,100 elevation). The truck was dying. Could barely keep 55mph with the pedal floored and two/haul mode on. Have repeated the trip multiple times with the same outcome. I was shocked. Felt like the experience I’d have with a Tacoma, not a Tundra.

 

You lose 3% power for every 1000ft in elevation in an NA motor. You’re towing pretty heavy at high elevation with maybe 230hp to the wheels. Performance is gonna suck.

Part of the reason new half tons are going to forced induction. They are not hindered to the degree NA engine’s are at elevation.

 

I'm familiar with Parleys and what it takes to pull 6k lbs over it in 100 degree summer heat. A stock truck gets worked pretty good to pull that hill with a big trailer - especially if it's a travel trailer with a lot of frontal area.

I'm around 4500' and pull trailers at 7k lbs+ at similar elevations and passes as SLC to PC via Parleys. I'm usually pulling an enclosed trailer with this weights, but occasionally a flatbed with higher weights. My '13 has pulled everything I've put behind it, but I wanted more power to make up for elevation.

Last winter, I installed a Whipple SC to do just that. Bottom line: it tows 1000% better at elevation with the SC.

No problem pulling in 5th except in 30+MPH headwinds. Grades up to 8% are usually fine in 4th. I pull a few 10% grades, but those are speed limited to where you are pulling in 3rd or 2nd simply due to low road or traffic speeds, not lack of power. No need to floor it, much less shifting up and down, and a much easier driving experience for the driver. My truck is set up to tow and haul with the factory tire size (E rated, mostly for tread depth and sidewall rigidity) and factory gearing. I almost always tow in S Mode and manually select gears, including downshifting before pedal position and load command a downshift. I monitor coolant and transmission temps; after a little tune tweaking, I haven't seen over 22x* transmission and 21* coolant temps, even with an 8.5 wide enclosed almost full loaded with a headwind at 65-70 MPH. My '15 sequoia 5.7 w/out a trans cooler sees 230 transmission temp on the freeway without a trailer, for comparison.

I wanted to install a SC when I bought the truck new, but couldn't afford it or justify it at the time. Toyota discontinued the TRD SC program about the time I paid off the truck and could afford the SC so I didn't get it done. Last year, I changed my mind and decided to get it done and I wish I would have done it from day one. Regular driving a SC'd tundra is as easy as drive at a stock vehicle, but way more fun when you decide to feed it some pedal. I rarely floor it or rev past 4k RPM because it makes so much usable torque starting basically at 2000 RPM. Zero regrets installing the SC over gears. I actually have a set of 4.88's for the rear axle sitting on the shelf while I was looking for a front set of 4.88's. I only plan on installing them if I get a new truck and this truck gets relegated to toy duty with 35's.