33's, armor, fridge, camping equipment, etc- 4.30 vs 4.56 gears

I know this has been beaten to death but it has been on my mind for some time and I need to ask for more opinions. I've been trying to figure out with gear ratio would be best for my setup.

Truck is a 2015 sport - 6-speed manual- I have bumpers, sliders and skids right now and will have it loaded up with camping gear, ARB fridge, water, fuel, etc most of the time. I would also like to eventually pull a 13-14’ inflatable boat with a 20hp motor. This truck is not my daily driver but there will be lots of highway travel to get to camping/off-roading areas. I will most likely have a 70mph speed limit (set by me) when loaded for camping. A Prinsu roof rack (Maxtrax, gear case, propane, chainsaw) and higher aluminum utility type shell will eventually be going on too.

I used the Grimm Jeeper calculator (http://www.grimmjeeper.com/gears.html) to see what the rpm would be at a given speed with the different gear ratios.

I have 255/85R16 Dick Cepek Extreme Country tires, which according to calculations are 33” tall. However, they actually measure 32” so this is the number I put into the calculator.

According to the calculator
Stock 3.73: (speed and rpm confirmed with ScanGauge II)

• 70mph = 2330rpm
• 75mph = 2497rpm

4.56:

• 70mph = 2849rpm
• 75mph = 3052rpm

4.30:

• 70mph = 2686rpm
• 75mph = 2876rpm

There is not a lot of rpm difference between the 4.56 and 4.30 gears at the indicated speeds so this makes it even harder to decide. The truck drives ok now but I lost with the armor and then again with the larger tires. Once I add the roof rack and a lot more weight from camping gear, etc, it will be a pig. I want to get back some of what I lost but I don't want to regret not going far enough.

I will be using ECGS for the assembled clamshell and third which will have lockers installed at the same time. Buy once, cry once.

Truck for reference...thanks!
eta- truck as of Nov 2019.

 

I have a 6 speed as well and I’ve decided to go with 4.56 gears when the time comes. Still gives me the option to move to 35s if I choose in the future and not regret spending money on gears that won’t even do the job anymore. That and I occasionally haul a fairly heavy trailer loaded with steel so the extra torque will be very welcome.

 

Go 4.56's. It was the best investment I've made to date. It makes technical wheeling much more enjoyable and gives the truck a little more pep around town. Also, ecgs did not recommend 4.30's due to quality even though the do list them on the site.

 

I vote 4.56s

Im running 4.10s in my 6spd with stock 265/65/17s and it turns about 3k rpms at 75mph. Totally livable, and the torque is addicting

 

Also I think it would be important to include the stock tire size with stock gears in your calculations. Mine were the shit dunlops (265/65/17) that measured 30.5. In factory form the truck ran right around 2500 rpms at 70 so increasing that to 2800 so will be so minor you'll hardly notice.

 

I only ran the stock tires for 250kms before I put 265/70R17 Duratracs on. I wasn't planning on going up to 33's and re-gearing so I didn't bother getting those numbers.

 

Don't think I'll ever go 35's but the 4.56 will be better if I ever do.

That's great to hear...also good info about ECGS and the 4.30's. I assume that the 4.56 thick cut gears are better suited than the normal 4.30 gears. This was also in the back of my mind when looking on their website.

Thanks for the input.

 

I have similar setup for the truck including your tire size. Also pull a teardrop trailer. I regeared to 4.56 and it's perfect. I have automatic transmission though. Before gearing, at 3.73 stock ratio or somthing like that, it was horrible.

 

Living with a little bit of a hit on gas mileage stings WAY less than regretting putting in the wrong gears and having to upgrade again. Go with the 4.56's. It allows you to continue to add in the future (more equipment and bigger tires).

 

Just adding that I found a new stock Tacoma with 265/65R17’s and measured them to be 29” on the truck. Plugged all that into the calculator and the difference (at 70 mph) was less than 300 rpm from stock to my setup with 4.56 gears. IMO that is absolutely doable and acceptable for what is gained.

 

I too, will vote 4.56. Like someone else mentioned, also gives you a little extra gearing if you decide to jump up a tire size.

 

Personally I find the manual transmissions to be overgeared stock. For 33s I would say your expected speed would be a huge factor and due to the calculator using calculations on the sizes I would not adjust to what you find on the truck. just compare the stock vs the new tires using the calculator. The main reason for this is the rotating diameter doesn't change just because the height on the truck compresses the tire doesn't change the overall diameter. if you want to be accurate use a soft measuring tape and measure the full diameter off the truck.

Now... if I could suggest anything, I would suggest going with a 4.10 set of gears for the manual for 33's. go 4.56 if you plan on going to 35's or 37's.
I would only pick 4.56 for 33's if I was staying at 60mph or slower all the time. otherwise the mileage will drop anytime you go faster.

I know that many of the gearing shops dont agree with me but my mileage and power on my truck speak for themselves. I have 35's and get 18mpg with armor and RTT for long distance traveling.

 

Bump for an updated picture.
Also, I contacted ECGS and with their reply I’m torn between 4.30 and 4.56 again

 

You have 33s, added weight, you have auto trans, and you tow. You shouldnt even be considering 4.30s imo. Regearing is too expensive to do it twice. Go with the 4.56s and be done with it

 

I have 285's and 4.3 gears with my manual. At GPS indicated 75 mph the RPM's are right at 3000. No plans to go with a bigger tire and I don't tow. For those reasons I'm glad I stuck with the 4.3 due to the RPM's. If I was towing often, I "think" I would regret my decision.

 

I have a manual transmission.

 

Just got with 4.56 you’ll thank yourself later. Granted I have a auto but with 4.56, full armor, and 285/75/17s my truck feels like it pulls harder than it did stock.

 

I commented on this thread a long time ago before I regeared. I ended up with 4.56s and I drive a 6 speed. I love it. MPGs do sort of tank after about 60 mph with 33s (my excuse to get 35s in the future), but every other aspect is worth it. I wheel fairly hard and have armor plus other stuff on the truck. Felt like I finally got my old truck back after putting in the 4.56s.

 

id still go with 4.56s personally. I have 4.10s with stock sized tires and a 6spd manual and it turns about 3k at 75mph. It's basically always in the powerband though

 

Glad you ended up with 4.56’s you mentioned in post #2. This is the way I’m leaning but ECGS basically said it’s a toss up between 4.30’s and 4.56’s so that’s why I’m second guessing my decision. I am worried about mpgs running at 70mph since there is a lot of highway travel to get to camping/off-road areas. Looking at the charts ECGS provided, the 4.30’s are only 150ish rpm less at 70mph than the 4.56’s.