Gear Ratio and Tow Capacity

Ghiers · June 4, 2020

Hello all,

I am looking into acquiring a travel trailer and would like to know everyone’s experience with towing capacity in these trucks. I have a 2018 Silverado LS 2WD with the 3.42s. According to the manual, this gives me a capacity to tow around 9200lbs. I also noted the same truck with 3.08s has a capacity of around 6400lbs. Is the truck really that effected by the gear ratio?

My dilemma is I am running 35x12.50x17 tires, however I don’t have a lift so not a big difference in drag. Based off some quick calculations I found online, my gear ratio is in the effect of 3.01. I’ve found a few trailers that I like that are between 27-31ft with a dry weight of 5-6k lbs. I imagine I will be hauling closer to 7k loaded. Does anyone have experience towing this amount of weight with these size tires on factory gears? Should I consider a regear before attempting this? Also, I live in AZ, so day-to-day driving is 99% flat, but I’m wanting to do my camping up in the mountains to get away from the heat.

dieselfan1 · June 4, 2020

Gear ratio is HUGE.

I just picked up a 25' Keystone TT. Dry weight is 4900. Loaded for the weekend it's 5850.

Here's an apples to oranges for ya

I have two 2018 Silverados.

1 is a dbl. cab bone stock 5.3 6spd 3.42.

It tows it with ease.

My other truck a crew cab standard bed, 5.3 6 spd 3.42 is running a 9" McGaughys lift on 37's. It struggles with it. Can't hold sixth gear for long wants to be in fifth . Slightest grade to maintain 60mph and she wants fourth gear, 2800 rpm and lots of gas.

With 35's your truck will do better than mine on 37's but not by much.

Will you be able to tow it? I say yes but plan on running in fifth gear most of the time and the occasional downshift to fourth and 3000+ rpms depending on how fast you want to go.

I wouldn't bother regearing unless you want to spend $1500-2000. You can buy a lot of gas for that

Let's see what others are saying....

Guys?

CamGTP · June 5, 2020

If you can do the labor yourself, doing a gear swap to 4.10's won't cost you that much. Paying a shop will cost you a lot more.

If it was me and I was going to keep the truck for a long time, I would be swapping gears and tuning the computer for the change. It would make everything better. More get up and go everywhere and will help pulling any trailer.

Ghiers · June 5, 2020

17 hours ago, dieselfan1 said:

Gear ratio is HUGE.

I just picked up a 25' Keystone TT. Dry weight is 4900. Loaded for the weekend it's 5850.

Here's an apples to oranges for ya

I have two 2018 Silverados.

1 is a dbl. cab bone stock 5.3 6spd 3.42.

It tows it with ease.

My other truck a crew cab standard bed, 5.3 6 spd 3.42 is running a 9" McGaughys lift on 37's. It struggles with it. Can't hold sixth gear for long wants to be in fifth . Slightest grade to maintain 60mph and she wants fourth gear, 2800 rpm and lots of gas.

With 35's your truck will do better than mine on 37's but not by much.

Will you be able to tow it? I say yes but plan on running in fifth gear most of the time and the occasional downshift to fourth and 3000+ rpms depending on how fast you want to go.

I wouldn't bother regearing unless you want to spend $1500-2000. You can buy a lot of gas for that

Let's see what others are saying....

Guys?

Do you tow with the trucks on 37s often? Any worries about transmission temp?

15 hours ago, CamGTP said:

If you can do the labor yourself, doing a gear swap to 4.10's won't cost you that much. Paying a shop will cost you a lot more.

If it was me and I was going to keep the truck for a long time, I would be swapping gears and tuning the computer for the change. It would make everything better. More get up and go everywhere and will help pulling any trailer.

If I had the tools I would, so I would let the professionals take it. This whole idea has me thinking diesel long term so I’m not sure.

thanks for the replies guys!

nominion · June 7, 2020

How often will you tow the trailer and what distance will you be doing it? If not everyday for long distances, I'd likely roll the dice and not change anything. If it turns out the truck struggles, reassess your situation.

Also, go to a travel trailer reseller and see if they will let you tow one to see how your truck handles it. That would give you a better idea.

dieselfan1 · June 7, 2020

On 6/5/2020 at 12:14 PM, Ghiers said:

Do you tow with the trucks on 37s often? Any worries about transmission temp?

I've only towed my 5800 lb TT with my lifted truck only to the lake and back around 200 miles total.

Trans never went above 195°

60 mph. Tow haul on. Left it in 5th gear. It downshifts to 4th a lot.

I basically ran the lifted truck on this one trip just to see how it would tow it. I probably will just use my stock truck to tow it most of time as it was a night and day difference.

My stock truck did this same exact trip the weekend before and got 13 mpg. Trans temps hovered at 190°. Only downshifted to 4th a few times while the lifted truck downshifted to 4th probably 15-20 times in 100 miles.

Barman84 · June 7, 2020

My 2014 came stock with 3.08s. It has a 9” lift and 35s.

three years ago and one transmission taking a dump due to overheating I bit the bullet. I installed 4.11s with corrected gear ratio it’s closer to 3.73s at the time I was living in washington state and driving hills everywhere up and down mountains and coastal roads.

my gas mileage actually improved. The drivability of the truck as a whole improved. Not to mention pulling my 7x12 trailer now feels like child’s play. Recently the army decided I needed to spend a year in korea so everything I own was packed into my trailer including my Harley. Total shipping weight came out to 7220ish pounds and to Texas I drove.

I can tell you right now if your gear ratio is below 3.42 with tires you’re going to absolutely hate towing with your truck period... it was a night and day difference for my drive to Texas compared to from Texas. Also, unlike the drive there my transmission never once overheated and I was pulling about 1800 more pounds back home then getting there.

Donstar · June 7, 2020

On 6/4/2020 at 2:33 PM, Ghiers said:

Hello all,

I am looking into acquiring a travel trailer and would like to know everyone’s experience with towing capacity in these trucks.

My dilemma is I am running 35x12.50x17 tires, however I don’t have a lift so not a big difference in drag.

Welcome to this forum and to RVing! I believe your truck will manage "as is" but your gas mileage may spoil the experience. I pulled a TT with my V6 for a couple of seasons and found it could manage the mountains and higher speeds without a problem. The harder it worked, the more gas it required. This isn't a big deal when gas prices are low, but was very expensive when I was paying over $5 a gallon! The easiest solution/compromise is to tame down your tire size. You will notice an improvement in efficiency and mileage even when you're not towing. Looking good can be expensive!

Barman84 · June 8, 2020

20 hours ago, Donstar said:

Welcome to this forum and to RVing! I believe your truck will manage "as is" but your gas mileage may spoil the experience. I pulled a TT with my V6 for a couple of seasons and found it could manage the mountains and higher speeds without a problem. The harder it worked, the more gas it required. This isn't a big deal when gas prices are low, but was very expensive when I was paying over $5 a gallon! The easiest solution/compromise is to tame down your tire size. You will notice an improvement in efficiency and mileage even when you're not towing. Looking good can be expensive!

Please for the love of Moses if you even care about your transmission and rear ended don’t follow this guys advice by saying screw it.

not only is that unsafe as hell its not proper. Ever see those awesome Ford raptors running down the road loaded with a toy hauler being hitched pulled and quads in the bed ass end damn near in the ground and front wheels barely useful? Yeah don’t be that guy. You wanna pull an RV either upgrade trucks to diesel, or had new gears and get some rear air as well.

KARNUT · June 8, 2020

How about going back to stock sized tires? That seems to be the most obvious choice.

Donstar · June 8, 2020

2 hours ago, Barman84 said:

Please for the love of Moses if you even care about your transmission and rear ended don’t follow this guys advice by saying screw it.

not only is that unsafe as hell its not proper. Ever see those awesome Ford raptors running down the road loaded with a toy hauler being hitched pulled and quads in the bed ass end damn near in the ground and front wheels barely useful? Yeah don’t be that guy. You wanna pull an RV either upgrade trucks to diesel, or had new gears and get some rear air as well.

My "advice" was actually to "tame down the tire size". A 25' Keystone can be safely pulled without a diesel, gear change or rear air. I mentioned his truck could manage "as is" but it was not my advice.

truckguy82 · June 9, 2020

On 6/4/2020 at 5:33 PM, Ghiers said:

Hello all,

I am looking into acquiring a travel trailer and would like to know everyone’s experience with towing capacity in these trucks. I have a 2018 Silverado LS 2WD with the 3.42s. According to the manual, this gives me a capacity to tow around 9200lbs. I also noted the same truck with 3.08s has a capacity of around 6400lbs. Is the truck really that effected by the gear ratio?

My dilemma is I am running 35x12.50x17 tires, however I don’t have a lift so not a big difference in drag. Based off some quick calculations I found online, my gear ratio is in the effect of 3.01. I’ve found a few trailers that I like that are between 27-31ft with a dry weight of 5-6k lbs. I imagine I will be hauling closer to 7k loaded. Does anyone have experience towing this amount of weight with these size tires on factory gears? Should I consider a regear before attempting this? Also, I live in AZ, so day-to-day driving is 99% flat, but I’m wanting to do my camping up in the mountains to get away from the heat.

My buddy is a contractor that tows around a 12k lb trailer almost everyday.

His tow rig (8.1 suburban) blew the trans and he started using his 2011 avalanche with a 5.3 and 3.08’s.

all he did was install a trans cooler, airbags, and a brake controller and he says it tows the thing just fine. He’s actually not going to buy another tow rig.

So considering the avalanche I believe is over 6k lbs, total weight is like 18k lbs. I think you could manage just fine even if you had 3.08’s.

swathdiver · June 9, 2020

3 hours ago, truckguy82 said:

My buddy is ...using his 2011 avalanche with a 5.3 and 3.08’s.

...it tows the thing just fine. He’s actually not going to buy another tow rig.

So considering the avalanche I believe is over 6k lbs, total weight is like 18k lbs. I think you could manage just fine even if you had 3.08’s.

Local driving on flat roads?

truckguy82 · June 9, 2020

4 minutes ago, swathdiver said:

Local driving on flat roads?

Yeah, but lots of stop and go.

def not doing any backroad mountains

swathdiver · June 9, 2020

1 hour ago, truckguy82 said:

Yeah, but lots of stop and go.

def not doing any backroad mountains

I know two guys with Yukon Denalis that tow 10K and 16K pound boats for short trips down here in Florida and they do it without any problems; until the DOT pulls up!