The best jeep ever made is this ecodiesel. The fuel economy is a thing of beauty, the torque to fall in love with and on a jeep capability, roof off freedom and a bed package, probably the best overall vehicle in existence.
Thanks again Casey! I have seen many posts and comments from others about regearing JLUs running 37” tires with the Ecodiesel engine. Some have suggested 4.56 or lower. I think it would be a big mistake to regear any Ecodiesel equipped JLU running up to 38” tires and here is why: While re-gearing from 4.10 (JLU Rubicon non-diesel) to either 4.88 or even 5.13 is perhaps essential in order to run 37” tires effectively and in order to reduce stress on the transmission in the long run, the Ecodiesel is an entirely different beast. The JL 3.6L Pentastar V6 has only 180 lb-ft @ 1400 rpm (peak 260 lb-ft @ 4800 rpm) while the 3.0L Ecodiesel (the JLU version) has 442 lb-ft @ 1400 (peak torque lasts from 1400 to 3000 rpm). For comparison, Fords new monster 7.3L big block V8 for the 2020 Super Duty trucks has 380 lb-ft @ 1400 rpm (peak is 475 lb-ft at 4000 rpm). The Ecodiesel equipped JLUs do not need lower gears for running 37” or even 38” tires effectively as the engine has a whopping 2.5 times more torque at low rpms compared to the 3.6L Pentastar V6. Also, running 33” tires with 3.73 gears is mechanically almost exactly the same as running 37” tires with 4.10 gears. The optimal gear for running 37” tires on an Ecodiesel equipped JLU is 4.10 which would take advantage of the entire engine torque curve and the entire transmission (based on its gearing) while also mechanically correcting the speedometer error with 37” tires. Therefore, I would submit that it is not worth the cost or the slight reduction of torque to regear an Ecodiesel equipped JLU as long as the tire size is 38” or smaller.
Ecodiesel only comes with 3.73 gears. You were recommending to not regear diesel equipped JLU but then you are saying the optimal gear to run 37s is 4.10. Hows running 37s with the stock gears on diesel JL? I am debating 3.6L JLUR and ecodiesel, not sure which one I should go if I want to run 37s with stock gears.
Dobok Kim - What I said is that the optimal axel gear ratio to run 37” tires on an ECODIESEL JLU is 4.10 because it delivers peak torque as low as 1400 rpm and it comes with the 8HP75 transmission (which is not the same automatic transmission as in the 3.6L Pentastar configuration). If you go with the 3.6L V6 in the Rubicon configuration and want to run 37” tires effectively, then you should strongly consider regearing to 4.88. The Ecodiesel delivers approximately 2.5 times more torque than the Pentastar V6 at 1400 rpm which means it would be fine running 37” tires on the stock 3.73 gears. Therefore, you would need much lower gears in the Pentastar configuration with 37” tires to end up at higher rpm where the gas engine delivers adequate torque. Hope this helps.
Gary M thanks, I’ve been searching online to find an answer and this really helps. I’ve seen a lot of 3.6 v6 owners running 37s on stock 4.10 gears claims it works very well without regearing. Most of them would be mall crawlers and that’s fine because I will be one of them lol (I do love outdoor activities in the nature but I don’t do hardcore off roading) It sounds diesel would be even a better option and the 3.73 gears isn’t an issue because of the abundant torque at low rpm. How well does the 8 speed automatic transmission respond with larger tires? Will it ever shift to 8th gear?
Thank you for experimenting and for posting your results. This is exactly what I was looking for before pulling the trigger and you just nailed it. The biggest shock was ~34 MPG on the stock 33” tires. That is truly amazing. Love your videos... please keep them coming.
Thanks for this video. Like a lot of people have already stated, this was definitely the video everyone was waiting for. It’s making the diesel that much more of a reason for the purchase. Thanks again for the awesome and informative content!
I’m not hating on the eco diesel, I have one, but have you mentioned the crankshaft position sensor wheel? It is located between the flywheel and the motor. When this $70 part explodes when you go to pass someone or get out of that mud hole you will be dead in the water like I was. So think about all the parts that have to come off to get to that magnetic wheel and sensor before you buy an eco diesel. It’s cost me almost $2,000 in parts and labor to fix it. By the way the flywheel bolts are one time use. Like I said, I’m not hating I’m just putting this information out there. The diesel mechanic has done 7 more of these same jobs since mine last year.
I like that you are willing to share your tests for Power and MPG with everyone, and I appreciate that you are doing all of the heavy liftings... Thanks. Don't let people's comments bother you (I don't think it does bother you.) The internet makes lots of people geniuses when they are less than average.
I'm really getting sold on this ecodiesel motor, of course, I'd need it in a 2-door. Honestly, the most shocking was 34+ MPG on the stock tires. Are stock tires 33" tall?
Great video. With the 37" tires and the computer thinking they are the stock tires, it is not compensating for them. I bet you reprogram with a Tazer JL and the computer will change shift points and and use your engine more efficiently. Should give you some of that lost kpL/mpg back. Obviously re-gearing would give you most of that back. These computer on these rigs now compensate a lot. Again great job Casey.
I just happen to happen to have a tazer JL sitting here :) It was on the dyno this week and will be the next video. It was interesting to see the power band and how it makes even more torque under load. Ill do another fuel run with my permanent tires, tazer Jl, and a moderately flat highway run after.. and a dyno run with bigger tires.
Fantastic info here Casey, great video! I'm surprised by the large loss in mpg due to the wheel/tire package, though 22 mpg isn't bad, it will certainly take a bite out the overall range of the vehicle on a tank of fuel. I'll be on the lookout for low weight wheel/tire packages, and I may now also start thinking about 35s . . .
Great information thank you 22 MPG on 37 mudds is very impressive although did not expect a loss of 10 MPG. You're only a hundred fifty pounds heavier with the swap, difference is the rolling resistance between all terrains and muds. Diesel Wrangler 👍
150lb of unsprung weight is a lot of additional rotational mass, especially through varying grades of terrain. Id imagine on a dead flat highway it would be a smaller delta. I did a video a while back talking about how much actual weight that rotational mass is equivalent too and it is surprising.
He has not corrected the computer yet either, which is going to throw off shift points and such. It’ll probably be a bit more efficient when the trans has the right values.
Been debating over a 4runner, Raptor, or the Diesel Jeep for a couple months now and my decision is final on the Jeep especially after watching your videos and the capability of that beast
Raptor and Wrangler/Gladiator are in a different world. Jeep Wrangler and Gladiator are very capable off road, probably the most capable. Raptor is a desert runner and wouldn't fit well in trails here. 4 runner is probably most comfortable and reliable.
Thanks for these videos, I've been considering getting a JLU with the diesel and its nice to see someone that has one and all the little things about it. Keep it up.
@@g496r500t I totally agree! The Government needs to get out of the car business! Like here in California it is next to impossible to bring in a Truck with a V8 engine because of the Emission B.S.
we all wish the state of California would stay out from under our jeep and trucks hoods! those enviro geeks push electric cars but never tell you how dirty the power that generates the electricity is. There are cleaner alternatives that will work in our cars and jeeps with out going electric!
It would have been great to see the original tires stood up next to the 37's for visual comparison. Hard for me to understand the size change. Thank You for sharing video Casey.
Impressive numbers, my diesel jk gets between 19 and 23 mpg with 33s depending on terrain. Worst mpg is on the highway because of the short 5th of the auto transmission
In modern trucks it's easier to mask the problems inherent to putting big tires on stock gears, thanks to more flexible engines and better transmission gearing. You can get away with it, but you inevitably lose power, burn more gas and put a lot of extra strain on the transmission. Yes, re-gearing is expensive, but it's necessary for the sake of longevity of components and maintaining as close to stock driving experience as you can. I never saw the sense of spending 50K+ on a vehicle, lifts, wheels and tires yet not forking over the extra 2K to have the axles geared properly to the application.
Tune would help greatly. Transmission would at least know what is going on with the bigger tires. And of course speedo would be corrected. If you went to 456s it would be that much better?
Ya I think the shift points were a bit low when hitting the gas. Im not sure it would make enough of a difference to go 4.56 and spend all that money. As well, 3.73 will have a bigger pinion which will be stronger with the torque and larger tires.
Nicholas Baldwin Going to 4.56 gears would be a huge mistake with the diesel engine. It is a torque monster at low rpms and it is therefore geared higher accordingly. With 37” tires, going from 3.73 to 4.10 gears would actually almost exactly compensate and mechanically correct the gearing and the speedometer. If you go with 4.56 gears with the Ecodiesel, you would likely lose the use of 1st and possibly your 2nd gear in city driving.
Its not apples to apples but on a JT on 37s with the 3.6 we observed about a .65 mpg difference between having the wheel speed corrected and not, probably because it disrupts the shift logic I believe 4.10s would put RPMs back to near identical to stock. That plus a lighter wheel with corrected speedo would probably add 3-4 mpg or about 1.25 to 1.7km/l I think I’m gonna do that on my gladiator diesel and run the Nitto Exo grappler in 37” for daily and snow driving and get 38” milestar on beadlocks next summer for wheeling trips
The gas motors will want to hold shifts longer which will need a tuner. In the next video, the Jeep is going to get a dyno pull and the diesel doesn't add much benefit by holding shifts. I will do a corrected fuel run after I add my tazer JL.
34mph is Awesome... But a 12mph loss?... That’s Crazy, and I would not have expected that...And with Cost of Fuel North of the Border. 😢 No matter what the Driving, it meant you had to push the Pedal closer to the Floor to try and maintain the same speed. 🤔
I would say that the close gear ratios of the transmission and how the turbo and engine generate torque, very little if any additional throttle input was required. We say some interesting results on the dyno when using its rolling launch control feature and how the engine can increase more torque under load with the turbo. Next video.
Lift is already sitting in my garage. Was waiting on my tie rod and drag link which just arrived. Im going to put the permanent wheels and tires on this week before lift. Stay tuned.
If I ever move to Canada I'll have to learn the metric system. They tried (and failed) to teach us back in elementary school here in the US, 40 years ago lol.
One constructive comment…. Make sure you put a stats sheet at the end where we can pause and look. Doing this verbally is not too practical. I have to watch the video again lol…. But great job and great idea!!
Voltage seems a little low at 12.9, had to replace the main battery in less than 1200 miles on my '19 JL 3.6, started exhibiting a lot of different issues, auto start stop & pace distancing cruise control errors to start then finally wouldn't start. now the start/stop battery is out but that just throws the auto start stop error, fine by me as now I don't have to turn it off every time. Great vid and content, wish I could have held out for the eco diesel but got a killer deal on new old stock 2019, had to pull the trigger.
Amazing videos! So much info in them! You should invest in the new Fujifilm X-T4 with the 80mm 2.8 Macro lens! That combo would give you insane sharp video results and its all stabilized! Just a suggestion since you will be going on some epic trails! Liked and subscribed
Your hand calculated will be off a little since the speedo is off. You got better than calculated. Also upgrading to 4.10 you’ll get your low end torque back. Especially off the line from a stop.
@casey 250 I haven't heard about the eco-D in a rubicon being an inch taller than a gas rubicon (the gladiator mojave is 1" higher than the gladiator rubicon) buy I have heard that the suspension on the eco-D was stiffer and it was explained because the engine is 400 lbs heavier which is also why they are rated less for towing( tleast in the gladiator). Keep up the great videos !
Casey, Thank you so much for the vid! I cannot believe the difference. I am on the opposite coast in NS. Question for you...do you think tires AT vs MT had a play in the difference? I know I am not buying my JT for fuel economy but HOLY CRAP, that thing does better than my Honda!!! LOL! I am dying to gte the JT with the 2.5" lift and 37's, but after seeing that, I might just stick with the oem stuff. I might do some trails and stuff, but never plan on rock crawling with it. Just a TON of Skiing and pulling of ATV trailers and boats! LOL! Thanks again!
Great video. I sold a very built JK with the pentastar because I hated the motor and transmission. I've been looking at the ecodiesel, will also run 37's. That said I tow a trailer with 4 wheeler. I'd love to see performance with your combination towing.
Hey Casey, I bought a Willy's eco diesel and am wanting to put 35s on. Did you have any issues with 37s rubbing while turning or hitting bumps? I know your fenders are higher but trying to ball park it with nobody really having a lift kit for it yet.
None, but only on the road and those tires had 3.25" back spacing. I am going to be putting on wider tires with less back spacing this week, keep an eye out for that vlog.
If the weight difference is 37lb per tire that’s only a 148lb difference, that’s a huge MPG drop for only the weight of one extra skinny person. It must be the aerodynamics of the 37’s causing the big drop in MPG
When the 148lb increase is rotational mass, it is more like 6x to 10x in static weight increase. Adding 900lb to 1500lb of static weight would definitely change fuel economy.
Now to me diesel and 37" tires on stock axles just doesn't seem like the best combination if you get in a bind more so if you get the 4 to 1 case. No it shouldn't make much of a difference on your in mpg power to weight ratio it has a lot of torque.
Good day, Love all of your videos. Super informative. I'm picking up my 2021 echodiesel next week. How many miles do recomend to break in before you really start to stand on the pedal. Thanks once again. Best Regards, Hermann from Southern California
Thank you so much once again. Your videos are so awesome and so informative. I'm chomping at the bit to get my new Rubicon echodiesel. Have a beautiful Easter weekend. Best, Hermann
Hey man, great video. m in the process of buying a JLRU and am debating on engine size. Biggest question is the 37s with the 3.73 end. It seems that there might not be a need for re-gearing. Question: how loud is the turbo diésel engine, I’ve read that it is very notable, very noisy. What’s your take! Thanx
You know its there and there is a whoosh sometimes from the waste gate. I notice it most going through drive-thrus or a cold start at camp. Nothing that has been troubling though.
I agree. I'm no longer interested in rock crawling off road except if they are in the way. The way the back seat of the JT folds is terrible. If it folded flat like the JL it would be some much more useful. This is the reason my other car is a Ram 2500 MEGA. The mega back seat folds flat vs the extra cab. The dog needs a place to ride!
where did you hear that the diesel has a higher lift? i figured the heavier diesel engine would add more compression. maybe jeep compensated for that? would love to find out if higher lift is true
There was a discussion about it on the JL forums. I need to ask someone to measure their front fender height on a stock gas model. I have my measurement from the front of the fender below signals at 34.75". The Ecodiesel uses different springs then gas models, for both the extra weight and the balance of weight with the fuel tank on the drivers side.
I think rotational mass of the tire is the biggest factor in fuel economy not rolling resistance. It might be a bit better an all terrain if it was lighter I would imagine.
@@Casey250 ..ok...just hard to believe 34 mpg but that's great news....never owned a jeep but seriously looking now...!!!!...looking forward to more of your videos and reports on this engine...my real concern is the reliability of this engine...thanks...
I might take it out once i get the proper rims and tires on with no lift. The backspacing on these trail ready beadlocks is an inch more then my Teraflex wheels so it would be hard to say. Also my tires I am putting on are wider.
Hi thank you so much great video I wanted to ask you what gear ratio do you have I have a JKU I’m right in the final stage of a hemi swap I put model 60s front and rear and 40 inch tires and I just couldn’t move out of it soundtracks with the stock engine thanks again
Hi what was the other options for the gear ratio can you get 410s with the eco-diesel thanks for taking the time to answer my question have a good one Katie thank you
@@Casey250 laughs I wouldn't rush to do it. But if your getting those numbers and you haven't re-geared it seems to me that 4.56 would be as far as you have to go 4.88 or 5.13 would be over kill. But for that engine I think 4.56 would be the sweet spot. I do have a suggestion for you though when you do the lift and calibrate the tire size you might run those test again because you might get better numbers.
I will do another fuel run, this time on flatter highway and my permanent tires, also I am planning to dyno run it again (next video has dyno results). I think id regear if I did a prorock 44 again and definitely for 60s.
I am a super newbie When it comes to wheeling and it’s hard to get good info, what would you run 31” Goodyear wrangler duratrac tires at on the road? I’m running them at 36psi and wondering if it’s too low?
@Casey 250, when you first got your jeep you got ~22 mpg, and in this run with the stock tires, it’s up in the ~30’s. Could you talk more about this? Thanks!
A couple thoughts. I was at a considerable higher elevation when I picked up the Jeep. Was mostly climbing elevation into the rockys as well. I find that the higher the speed with stock tires the lower the fuel economy. 80 to 90km/h on stock tires seemed to be better then the 110 to 120km/h I was traveling through the rockies. I did another fuel economy test with 47s and recalibrated speedometer and it will be up tomorrow in a video.
I average 21.5 mpg with my EcoDiesel running 75 mph with Mopar 17" Beadlocks and Toyo Open Country RT's. That's with 75% Hwy driving. If I run 75% City my mpg goes up to 26 mpg. I would have thought it would be the other way due to the rolling tire on the hwy would have Inertia keeping it rolling. I live in central Florida so the only grades we have are overpasses. Is the rolling resistance of the tire tread that great to cause the hwy mpg drop?
74lbs factory. 111lbs with those. My new wheel assemble is 118lbs. I did see better fuel economy in tomorrows video on a flatter highway and recalibrated speedo.