Your 3.0L Diesel's MPG's, share with the class.

[SolarWizard]

Do you still have a FAD and what gearing? that’s great

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[rubileon]

Maybe nuts, but this is why I waited for the diesel. When you are driving over 22k per year, milage is an important factor.

Our highways are mostly around your 65mph and my 3.6 auto rubicon shows 33.6 mpg... stock wheels though. Not sure if it'll go down to 24 mpg with bigger wheels but still it's worth it not to deal with modern diesel complications.

 

[Compression-Ignition]

 

[Themistocles]

I picked mine up in Idaho and drove it back the next day to Virginia. 2600 miles, was cruising about 75 most of the way. Averaged 28.6 for the first two days, then hit a monster quartering headwind in Nebraska all the way through Missouri...that dropped me to 26.2. By the time i got home i had beought it back up to 27.7.

Now mixed driving around town and to work, seeing about 26 even.

 

[Motoristx]

Just got back from a trip, did Valley of the gods, Moab with trails and some Colorado trailes in the San Juan mountains and did Holy Cross. I put about 3000 miles on this trip, and just turned 10,000 miles last week.

I'm on 38's, stock 3.73's, and 3.5 inch lift, with about 30 psi for highway driving, and about 10 psi for trails.

Most of my highway miles were about 83 mph, and there was some trail driving too. I actually got better mileage when mixing the trail driving with highway driving.

I spent more time on the Holy Cross trail than any other trail, about 7 hours, and I used 1/8 of a tank. not very scientific... but that's all I had to go by.

On the Highway, I got about 18.5 mpg ave. Again this was like 83 mph most of the time. One tank I got 26, but I think it was combination driving 80% highway and I was driving slower. I didn't keep track of the regens, I really don't know when it's happening, and I was looking at the beautiful scenery most of the time. Also the DEF draining super fast on this trip, lasting about 3500 miles for 4.8 gallons. I was 20 miles from no start.

My worst tank so far was 15.4 mpg, I'm assuming I was hauling ass, and hit a regen.

When I'm at home, I still drive 80% highway and keep it around 73 mph. I get close to 21.5 mpg.

If your wondering about the odd speeds. I really try to keep it under 10 mph over the speed limit, so I stick to about 8 over... I think it keeps me out of tickets unless I hit a speed trap...

Hope this helps.

 

[LowBama]

Team,

I have a JLURD with factory tires and suspension. My computer says I’m getting 26ish but my hand calcs are giving me 23ish. I’m doing 70/30 highway/city with max speed around 70 and feel like I drive it pretty easy in the city. Is the MPG seam normal and does your computer over report MPG like mine? Any input is appreciated.

 

[Compression-Ignition]

Team,

I have a JLURD with factory tires and suspension. My computer says I’m getting 26ish but my hand calcs are giving me 23ish. I’m doing 70/30 highway/city with max speed around 70 and feel like I drive it pretty easy in the city. Is the MPG seam normal and does your computer over report MPG like mine? Any input is appreciated.

I don't recall if the computer reported our mileage high low or spot on. I will say 70mph is out of the sweet spot for sure, mpg's take a hit that compounds after a certain speed. Is it flat where you live? How long is your commute? Do you have a way of monitoring regens?

The other day was the first time we got unlucky with a regen. My wife looks at the monitor every now and then, but she missed the start of a regen. I'm assuming the regen started at 80% soot mass load, and not seeing that it was in regen, she shut the engine down when the soot was only down to 71. I surmise that was enough to get her out of regen, but not very far. This sort of thing could be happening to people all the time. It would obviously happen more to people who drive in town frequently, but it could still happen to people who drive at highway speeds more often. It would just require unfortunate timing here and there.

I'd say your mpg's seem a little low, but there are too many variables. Among them is some vehicles just get better fuel mileage than others.

If you use cruise control often try keeping it off and perhaps give the manual mode a shot. Anything flat or heading downhill say 50mph or above (while coasting or only slightly accelerating) let it sip fuel in 8th gear. Going uphill under mild acceleration try to keep the engine in/at peak torque output <<<which ashamedly, I have no clue where/what that value is, I was assuming somewhere between 1750-2200 RPM's. If you want to boogie throw it back in regular old auto, and let the computer do it's thing.

Other tried and true method is slow down.

 

[LowBama]

I don't recall if the computer reported our mileage high low or spot on. I will say 70mph is out of the sweet spot for sure, mpg's take a hit that compounds after a certain speed. Is it flat where you live? How long is your commute? Do you have a way of monitoring regens?

The other day was the first time we got unlucky with a regen. My wife looks at the monitor every now and then, but she missed the start of a regen. I'm assuming the regen started at 80% soot mass load, and not seeing that it was in regen, she shut the engine down when the soot was only down to 71. I surmise that was enough to get her out of regen, but not very far. This sort of thing could be happening to people all the time. It would obviously happen more to people who drive in town frequently, but it could still happen to people who drive at highway speeds more often. It would just require unfortunate timing here and there.

I'd say your mpg's seem a little low, but there are too many variables. Among them is some vehicles just get better fuel mileage than others.

If you use cruise control often try keeping it off and perhaps give the manual mode a shot. Anything flat or heading downhill say 50mph or above (while coasting or only slightly accelerating) let it sip fuel in 8th gear. Going uphill under mild acceleration try to keep the engine in/at peak torque output <<<which ashamedly, I have no clue where/what that value is, I was assuming somewhere between 1750-2200 RPM's. If you want to boogie throw it back in regular old auto, and let the computer do it's thing.

Other tried and true method is slow down.

Mostly flat I live in South Alabama. Most of my miles are interstate where I just set the cruise on 70. I’m not trying to hyper mile or anything. Just trying to see if I’m inside what others see or if something is out of sorts. How do u monitor regens? Is there a way to do this without buying an expensive add on?

 

[Compression-Ignition]

Mostly flat I live in South Alabama. Most of my miles are interstate where I just set the cruise on 70. I’m not trying to hyper mile or anything. Just trying to see if I’m inside what others see or if something is out of sorts. How do u monitor regens? Is there a way to do this without buying an expensive add on?

Plug in a Bluetooth adapter or a cable at the OBD II port that sends information to your monitor of choice (current smartphone, old smartphone, tablet, proprietary monitoring screen made by whomever). I use a scangauge II. Somewhere on this board there was a decent discussion going on what all people were using. IIRC it wasn't the threads main aim though.

Old dirty bastard! Trust me, just click the link lol!

 

[jeme]

Pardon my ignorance - I am considering a diesel wrangler and following the threads. What is a regen? Thanks so much.

 

[Compression-Ignition]

Pardon my ignorance - I am considering a diesel wrangler and following the threads. What is a regen? Thanks so much.

This topic probably deserves it's own thread.

DPF = diesel particulate filter (looks like a big resonator or muffler section in the exhaust system)

Regen = regeneration process (DPF is heated up to burn/clean/remove soot trapped inside the the DPF)

I'd go look at some manufacturers websites that can explain the process in full detail. Also there are I'm sure tons of videos on YouTube that can get you up to speed.

 

[jeme]

Thanks so much. So does the vehicle do this itself or do you need to initiate it?

 

[Compression-Ignition]

Thanks so much. So does the vehicle do this itself or do you need to initiate it?

No operator input required, unfortunately.

 

[WXman]

Different application but same powertrain. My Eco is seeing 21-22 in mixed driving. I get 11-12 when totally loaded and towing to camp sites. I do have the 3.92 gears, but with 34" tires it's effectively like having a 3.65 gear now. Also, the dash display is consistently 1.0 to 1.2 MPG optimistic in this truck for some reason. Never saw that with the gas engines in Jeeps or Rams.

 

[Motoristx]

Team,

I have a JLURD with factory tires and suspension. My computer says I’m getting 26ish but my hand calcs are giving me 23ish. I’m doing 70/30 highway/city with max speed around 70 and feel like I drive it pretty easy in the city. Is the MPG seam normal and does your computer over report MPG like mine? Any input is appreciated.

On stock tires, I got close to 22.5 mpg driving 65 - 73 mph. I do a lot of highway driving and Houston is pretty flat, other than all the overpasses. The calculation is hit/miss. it seems to be close when I'm taking it easy around town. Once on the trail, or on the highway is starts to diverge. Same is true now that I'm on 38's and 3.5 lift.

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