2021 40” Rubicon Diesel Build

[40”JLURD]

So you wish you wouldve gone for the 392? despite being 25k more than the ED and at 12 mpg vs 20-30? or vs the 15 youre getting now? haha

Yes

I’d rather hang the 392, get 3mpg less and have a ton of power

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[therealmateo]

Yes

I’d rather hang the 392, get 3mpg less and have a ton of power

Yeah, I feel ya. But I'll tell you what, I get ~12 mpg (8 if climbing or a headwind) in my jkur right now which is about 240 miles per tank and it sucks having to stop on roadtrips every 200-240 miles. That's why I'm looking at the ED, it'd be nice to get at least 400 miles out of a tank. The reason I'm intrigued with your build is that I have some 40's in my shop right now waiting to be put on something. I could throw them on my 55 willys crawler but its already on 39" KR2's that hook up good.

 

[40”JLURD]

Yeah, I feel ya. But I'll tell you what, I get ~12 mpg (8 if climbing or a headwind) in my jkur right now which is about 240 miles per tank and it sucks having to stop on roadtrips every 200-240 miles. That's why I'm looking at the ED, it'd be nice to get at least 400 miles out of a tank. The reason I'm intrigued with your build is that I have some 40's in my shop right now waiting to be put on something. I could throw them on my 55 willys crawler but its already on 39" KR2's that hook up good.

If that’s what you want out of an EcoD then keep looking.

Ive never got over 250 miles out of even 1 tank since the lift / 40’s

I typically average between 15.3 - 15.5 MPG with normal combined city / highway driving. Horrible.

 

[therealmateo]

If that’s what you want out of an EcoD then keep looking.

Ive never got over 250 miles out of even 1 tank since the lift / 40’s

I typically average between 15.3 - 15.5 MPG with normal combined city / highway driving. Horrible.

Yikes that sucks. If I did get one I would do a full delete and tune as I dont have to worry about emissions...hopefully that would allow it to get decent mpgs despite the bigger tires.

At that rate I might just get a TRX instead of the 392, would be nice to be able to haul stuff...and get decent range out of a tank.

 

[40”JLURD]

Yikes that sucks. If I did get one I would do a full delete and tune as I dont have to worry about emissions...hopefully that would allow it to get decent mpgs despite the bigger tires.

At that rate I might just get a TRX instead of the 392, would be nice to be able to haul stuff...and get decent range out of a tank.

TRX for the win!!!

EcoD would probably work great with a full delete and tune. Unfortunately for me I’m in Nazi California so that’s not an option for me.

If it is an option where you live then I’d probably go that route. A fully deleted EcoD would probably get double the mileage of mine.

If you end up-doing it please report back and let me know how it works and what kind of power / MPG you get.

 

[40”JLURD]

Yikes that sucks. If I did get one I would do a full delete and tune as I dont have to worry about emissions...hopefully that would allow it to get decent mpgs despite the bigger tires.

At that rate I might just get a TRX instead of the 392, would be nice to be able to haul stuff...and get decent range out of a tank.

Also word of advice - don’t over gear your EcoD like I did.

The 4.88 gears are too deep for the available RPM range of the motor.

If I were to re-gear I would choose 4.30 for better MPG, or at the very deepest 4.56.

Definitely nothing deeper for 40’s.

If I had the money I’d re-gear to 4.30’s but I already blew my whole wad on the build so I’m stuck with what I have for now.

 

[Howardlv22]

Yikes that sucks. If I did get one I would do a full delete and tune as I dont have to worry about emissions...hopefully that would allow it to get decent mpgs despite the bigger tires.

At that rate I might just get a TRX instead of the 392, would be nice to be able to haul stuff...and get decent range out of a tank.

Remember, and nothing on this guys build, but he's the only ECOD I know getting that bad mileage. Me my babysitter and our friend all have them and mine is on 4" of lift with Patagonia 37's and I can't get worse than 21.5 MPG EVEN IF I TRY! stock I averaged 27-31 and now I get 22.5-24 on trips and 21.5-23.5 combined. And I have a heavy bumper tire carrier etc. My friends on 35's are getting 22-24.5 combined.

 

[therealmateo]

TRX for the win!!!

EcoD would probably work great with a full delete and tune. Unfortunately for me I’m in Nazi California so that’s not an option for me.

If it is an option where you live then I’d probably go that route. A fully deleted EcoD would probably get double the mileage of mine.

If you end up-doing it please report back and let me know how it works and what kind of power / MPG you get.

HAHA. yeah I'm in the bay area of commifornia right now but kept my house in WY and everything will be registered there so I won't have to worry about emissions.

Remember, and nothing on this guys build, but he's the only ECOD I know getting that bad mileage. Me my babysitter and our friend all have them and mine is on 4" of lift with Patagonia 37's and I can't get worse than 21.5 MPG EVEN IF I TRY! stock I averaged 27-31 and now I get 22.5-24 on trips and 21.5-23.5 combined. And I have a heavy bumper tire carrier etc. My friends on 35's are getting 22-24.5 combined.

Good to know thanks. I'm sure the 40's coupled with the tons and driving style have a lot to do with it but good to know if I went with 37's instead of 40's I won't kill my mpgs

 

[RusM]

This is my up travel in the rear as of yesterday

What bumpers do you have?

 

[40”JLURD]

Remember, and nothing on this guys build, but he's the only ECOD I know getting that bad mileage. Me my babysitter and our friend all have them and mine is on 4" of lift with Patagonia 37's and I can't get worse than 21.5 MPG EVEN IF I TRY! stock I averaged 27-31 and now I get 22.5-24 on trips and 21.5-23.5 combined. And I have a heavy bumper tire carrier etc. My friends on 35's are getting 22-24.5 combined.

And are any of you re geared? I am guessing no.

I said above do not go with too deep of a gear or it will kill your MPG

 

[40”JLURD]

What bumpers do you have?

Rebel off-road for the rear
Evo front

 

[40”JLURD]

Remember, and nothing on this guys build, but he's the only ECOD I know getting that bad mileage. Me my babysitter and our friend all have them and mine is on 4" of lift with Patagonia 37's and I can't get worse than 21.5 MPG EVEN IF I TRY! stock I averaged 27-31 and now I get 22.5-24 on trips and 21.5-23.5 combined. And I have a heavy bumper tire carrier etc. My friends on 35's are getting 22-24.5 combined.

And I take your silence as yes I am correct you and all your amigos have not re geared. That’s cool and I’m happy for you that your rigs are doing what they are supposed to do; and what I bought mine to do.

GET GOOD MPG WITH BIG TIRES

(before I foolishly over geared it per my builders insistence - I wanted 4.56’s which in the end of the day I was right and would’ve been soooooo much better off with the 4.56 that wanted rather than the 4.88 he insisted would be “better” and I got)

But yes your Jeeps are all drastically under geared now. Hi here and see for yourself. The funny thing is SLIGHTLY “under geared” from factory is exactly what you want to be and is ideal with this motor.

Go check your effective R&P ratios with your new combinations for yourself here.

https://www.intercotire.com/tire_size_change_gear_ratio_calculator

The Eco Diesel needs to be slightly under geared to achieve optimal fuel economy with bigger tires. Which is exactly what you’ve done by increasing tire size without re gearing.

 

[40”JLURD]

Finally got the rear inner fenders painted. It looks so much better now!!! … except the hard anodize black I did on the corners is already fading damn it… we’ll at least it’s holding up great so far on the GenRight tire carrier

Aside from that got the front axle pushed forward to the absolute max the Evo Pro Long Arm kit will allow. This has been awesome in finally allowing the 40’s to clear with no rubbing and the additional caster I gained was a much needed improvement in ride quality and handling . I’m now at 5.4* Caster

The bad news….

The Evo Spec King Springs are sagging like your grandmas tits

So thank you to @AccuTunedJL for helping me pick out a new set of professionally tuned Eibach springs for my JL! I can’t wait to see what it rides like once I can afford them and the install lol

 

[Moto_21]

Finally got the rear inner fenders painted. It looks so much better now!!! … except the hard anodize black I did on the corners is already fading damn it… we’ll at least it’s holding up great so far on the GenRight tire carrier

Aside from that got the front axle pushed forward to the absolute max the Evo Pro Long Arm kit will allow. This has been awesome in finally allowing the 40’s to clear with no rubbing and the additional caster I gained was a much needed improvement in ride quality and handling . I’m now at 5.4* Caster

The bad news….

The Evo Spec King Springs are sagging like your grandmas tits

So thank you to @AccuTunedJL for helping me pick out a new set of professionally tuned Eibach springs for my JL! I can’t wait to see what it rides like once I can afford them and the install lol

Ill install them for you

 

[Moto_21]

For a six pack

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