3.0 D-max reviews?

[6DoF]

looking at a 2021 Tahoe for the wife that would replace her 07 WK and my 08 GMC 2500. 1 less car around to deal with, a much nice ride, and i'll have the 55 soon (hopefully) for truck bed stuff. but we have ample trailers too.

thoughts on the new mini I6 diesel?

[6DoF]

the whole oil-pump belt thing doesn't really scare me much in the grand scheme of things. that's the only down side i've seen.

other than there being ZERO aftermarket for them yet cuz EPA ... fawk the man ...

[xj_man_646]

Other than typical modern diesel concerns and the belt driven oil pump I think they're pretty solid. A friend's dad in SE MI leased one of the trucks and loves it so far. Unconventional to most diesels it has an air to water intercooler so that adds a bit of complexity to the charge cooling system.

[6DoF]

i'm excited to try one tonight. the wife really liked the diesel JLUR over the 3.6 JLU we drove on Saturday. i also made her drive a 2021 manual window, manual trans 2dr and it was really good, she actually liked it. enough that i don't think she could convince herself that the $61k JLUR was worth anywhere near that much more than the $29 JL.

[Cobound]

I'm so glad my wife likes her 2 door JK Sahara

[6DoF]

so the 3.0 was nice, but defiantly not "peppy". 100% would buy a Banks derringer for it.

last night we basically decided to not decide now. we are pushing off any purchase cuz it doesn't really matter. if we really wanted to we could both get new trucks, or combine the WK and GMC into one, or simply keep going how we are. to help the just wait decision, she drove my truck to work at the hospital today to park it in the city and see how it goes. last night it was all good, but half way to work the power steering started whining and by the time she got to the tight ally and parking lot there was no power steering. "sorry babe, happy anniversary"

[6DoF]

found a buddy who gave me a GM discount code!! ordering a 2021 Tahoe with the 3.0L D-Max this week. i guess it's like a 12wk lead time.

[nblehm]

Didnt even know you could get a tahoe with a diesel.

[xj_man_646]

Yep you can get the Tahoe and Suburban with the baby Duramax now.

[nblehm]

I dont get why people want the diesels with all the emissions junk on them but cool they come in more than 3/4 - 1 ton trucks

[6DoF]

Originally Posted by nblehm

I dont get why people want the diesels with all the emissions junk on them but cool they come in more than 3/4 - 1 ton trucks

i obviously agree to a point, that's why i'm building with an old mechanical pre-BS cummins. however at this point they've been messing with the systems long enough they at least aren't new.

for me it's cost vs engine on this. trading my 2500 GMC and the WK in on this Tahoe. the 55 will eventually be my heavy hauler, but i need this to still be able to tow the YJ in the enclosed. of the 3 engine choices, the 3.0, 5.3 and 6.2, i'd rather have the 6.2. however it's only available on the highest package and costs like $10k more. between the 5.3 and the 3.0, the torque of the 3.0 is a no brainer. 383lb-ft @ 4100 vs 460lb-ft @ 1500. plus i've seen magazine reviewers getting upwards of 27mpg highway with it, and Banks should release some their magic box for it this year.

[xj_man_646]

Yeah, the technology isn't new, but it is basically as unreliable as its ever been as far as nuisance faults. I agree with Nate. 2007 will be the latest light duty diesel I ever own. Hope it works out for you.

The one thing I found odd about the 3.0 is that it uses an air to water charge air cooling system, so there is a bit more complexity to this system even over your typical diesel engine. Not that those systems are new either, just found it interesting.

[xj_man_646]

Looks like I already said that. Oops.

[6DoF]

i'm actually going to be using a water-air on the 55 as it gets built up. i like the tech and am not worried about it. hell, it's used in a ton of boosted gas engines factory as well.

[xj_man_646]

Yep that is true. It was a bit of a surprise (to me) that they went this route on the 3.0. My thought was always that the air to water charge cooling is really only advantageous when you can't get the airflow you need over a large air to air cooler, like you typically find in the cooling stack of a full size truck.

[6DoF]

Originally Posted by xj_man_646

Yep that is true. It was a bit of a surprise (to me) that they went this route on the 3.0. My thought was always that the air to water charge cooling is really only advantageous when you can't get the airflow you need over a large air to air cooler, like you typically find in the cooling stack of a full size truck.

air to air is just a cheaper, and probably more robust, set up. water to air can be more efficient in a smaller package, and gives you more options for routing and placement. plus the ability to run an ice tank in racing applications.

so i've been doing more reading on it recently, make sure it's what i want. short of some currently unknown manufacturing defect that kills stuff, the engineering seams really solid. they really didn't seam to skimp on this thing. some magazine reviews saw like 27mpg, and one even achieved 40mph in a hyper-mileage challenge. the torque "curve" isn't really a curve at all, it's basically ecu limited. it supposedly holds 460lb-ft from 1500-3000rpm, with still 95% of that from 1250. a good tuner should be able to unlock some major goodness!

[xj_man_646]

The world of diesel engine tuning is constantly evolving and more and more are getting out of it all together as far as I know. EZ Lynk was just hit this week for their deletes. I wouldn't be surprised if its limited to emissions friendly tunes in the 100HP-ish gain realm. Still decent, but they can't really go hog wild anymore as far as I know.

[Cobound]

So, about that '21 Tahoe

Anyway, my JT has the 3.0 Diesel and I love it. Power, albeit a bit of a delay at takeoff, torque...the Banks Pedal Monster helps the pedal feel for sure...I have the Deringer as well but never installed it. Heard it's potentially troublesome when towing...and I do a fair bit of that w/ a SXS and now my enclosed trailer. It legit pounds DEF when towing, good lord!

Still running stock gears (3.73) on 37s and it's got snort - could probably go to 4.56 or 4.88 for a bit more pull, but not really worth it at this time.

I've had it to the mountains a few times, and while it gets solid fuel mileage, it could be a bit better. Friends with bigger meats get better, but I'm guessing that's all in drive style...so I'll take the 17-20 that it varies and live w/ it. I mean, it's a brick, right

Towed the SXS to Moab last year and got about 13 avg...going speeds above 70 so I could slow it down bit and improve, but fukall. Going to be super curious to see how it tows this year, with an enclosed trailer loaded w/ a SXS and some camping gear.

Lord knows I'm not an engineer - but you guys have any more feedback on these engines now that they've been out for a bit?

This is the beast I'll be towing -

[xj_man_646]

I have heard surprisingly little about the latest generation of EcoDiesel. I think the shift to low-pressure EGR (taking an EGR sample post-DPF where there is much less soot) was a wise choice for that engine. The previous generation had loads of issues that I think could be resolved with that move.

I worked on an under-boost diagnostic for the previous generation and learned at that time that low compression right from the factory was something they were plagued with, to the point where the boost response from a stock vehicle with low compression looked like an engine with normal compression and a 4mm hole in a boost hose.

For the trouble we dealt with, I did always enjoy the way the EcoDiesel drove, especially when paired with that 8 speed ZF.

I think I've heard rumblings of CP4 injection pump failures hitting the EcoDiesel now, but that is more of a global problem with all applications running the CP4, not isolated to FCA.

[Cobound]

Oh, I’m good.