VictorLin0725

Hey there,
Looking to purchase a 2018 Lariat Screw V8 4X4 in the near future and was wondering what axle ratio would be ideal? I normally do 50% city driving 40% highway driving and 10% towing (boats and cars...nothing big). Looking for a ratio that would be a nice balance between acceleration, mpg, and towing. 3.31, 3.55, 3.73 Any reommendations? Also with the new 10-speed auto...will the ratios still make that much of a difference?

First post here, thanks in advance for any input.

Cheers,
Victor

icantdrive55

Most of the vehicles on the lot with that configuration will come with either the 3.31 or the 3.55 axle. The 3.73 is standard spec with the HDPP, but unlikely you'll find one of those unless you order a 2019. For the type of use you describe, either of the lower ratios will work; my preference would be the 3.55 with e-locker. That ratio in my truck results in the engine spinning about 1700 RPM at +/- 65 MPH.

UncleG

3.73 is a good all around gear.

gatorblue92

I've got the 3.31 axles in mine and I think its just fine for the mixed use you are planning. I'm also leveled with 33's.

schmenke

With 90% of your driving being combined city/highway, I'd suggest the 3.55, or as gator mentioned, perhaps even the 3.31.

OCMike

iTrader: (1)

The 3.73 E-Locker also gets you a 9.75" rear differential, at least in 2018. If that sort of thing is important to you.




Mike

2AF150GA

With the 10-speed you can't really go wrong with any ratio. I ended up with the 3.15 because I don't really tow but maybe twice a year and it's no where near the capacity the truck is capable of. I get 20mpg city all the time (hand calculated). TFLTruck just did a video where a 2018 F150 XLT 2wd with the 5.0 and a 3.15 rear did a drag race against a 2019 Ram with the 5.7 and eTorque (I believe the rear axel was a 3.55) and the F150 smoked it (we also had a weight advantage as well). Here is the video:
With such a broad spectrum of gears in the 10-speed the F150 is fast no matter what you get (we are lighter than the competition as well). You'd be good with a 3.31 or 3.55 unless you want the bragging rights of the 3.73 but it's over kill for what you stated you use the truck for. Ford did a great job with making the F150 good at everything. Fast with good gas mileage is hard to do but they did it.

RL1990

Anyone else remember the days before the internet when you bought a vehicle without knowing all the specific details about every nut and bolt? Back then unless you were a mechanic you didn't know or give a #### about axle ratios, lb/ft of torque or even how many HP the engine had. Trucks were bought to work; not drag race or be Mercedes replacements.

You through your stuff in the bed or dropped a trailer on it and took off and you expected to the truck to get the job done. Anybody ever remember their Dad wondering if the axle ratio of his truck was sufficient; I sure the heck don't? Folks back then didn't care about acceleration times of a loaded truck or was the least bit concerned about driving it foot to the floor to keep up. Durability was more important than 0-60 times. Those exceptionally weak engines (compared to today), 4 speed transmissions and God knows what axle ratios back then managed to do all the same work we use trucks for today. That old 300 straight six or 5.0 and 5.8 V8s, and AOD transmissions were pushed hard, ran on straight dino oil and probably not meticulously taken cared of yet managed to get the job done.

What I'm saying is that Ford has done all the math for you. They have already calculated the optimum axle ratio to GCWR to engine matrix. Pick the one that meets your needs.

RL1990

The Coyote's advantage is the same as the Ecoboost against the Ram. The Coyote's DOHC 32 valves allow the engine to breathe better than the Ram's 16 valve pushrod engine. The more air you can get in and out of an engine the more power it can make. The Ford V8 puts out more power per liter than any of the competition.

VictorLin0725

Thanks for all the responses, you guys helped out a lot! I'm the kind of guy to buy a truck and rarely tow with it just because I think its a good all rounder vehicle. Judging by the responses I think the 3.55 would should suit me just fine...good balance of everything. Also, does running the rpm slightly higher affect the longevity of the engine? Its the only downside I can see choosing something in a 3.55 or 3.73.