Considering Diesel

[Seamus]

I cleared my mileage before I left and left it on 50 mile increments. It jumped between 26 and 29.7 thru the 350 miles. I'm saying overall on the 350 it prob got 27 as an overall average. It hit 30.3 previously on a 150 mile run.
I'm saying on a Yukon, 30 MPG is potentially attainable, but probably at this big boxes top end. For as big a vehicle as it is and all it can haul and do, I'm elated at anything above 25. Many crappy 4 cyl cars don't get 25...
The key for me is dependability and longevity. If I can get both from this combination with reasonable maintenance I will be more than happy. So far still in honeymoon stage and all is great!

I can agree. The mileage really ticks up if 65-70 mph. A lot of the videos with high MPG are at lower speeds and I dont know if the AC is on. I get 24 MPG easily. Anything above takes effort and a lower speed. My wife has a MB GLC300 4 cyl turbo. For perspective she averages 22 and a high of 27 mpg. This huge truck is getting 24 mpg which is insane. Love the torque, pulls strong in city driving.
The B Duramax was a must for me, unfortunately there has not been any white frost 2WD Denali XL here in Florida that could be had. Found one for 15k over sticker, not an option. So landed this Sierra Denali with ultimate package and am very impressed and happy for now. When the insanity stops will flip into the Denali Yukon XL. This Duramax is a winner though!
I do my own maintenance here, rockauto has best price on the oil and filters. 7 qts and a filter. No more than any gasser. Fuel filter is cheap and easy to get to. I too am in honeymoon stage but been researching for 3 years. 2 months in seems like its going to be a good ride.

 

[Rangerdeepv]

If you can't deal with DEF and large trucks do not get the diesel. I try to go to the diesel pumps which get used the most in higher traffic areas and always have some DEF in the garage. This Yukon is an amazing vehicle to drive with the diesel. A friend has a '19 Tahoe with the 5.3 and it is ok and reminded me of my '17 Sierra double cab. After test driving the diesel Yukon it was love at 1st drive. It now has close to 1K miles and still in the honeymoon phase. 27 mpg overall is amazing for a vehicle this size. Have not had a chance to pull the bass boat yet but that day in quickly approaching. I did have to pay a couple k over sticker but this had the exact options I wanted. Not black or white, had to have the diesel, sunroof and 2nd row bench seat. Very tough to find with the bench but well worth the wait. It does have the 2nd row entertainment which I will not use but the wife and dog will probably have lots of fun with that. Love this vehicle so far!

 

[Decreed_it]

I'm in the pro-diesel camp w/ @Stbentoak and others, we just ordered a Denali XL Duramax for all those previously listed reasons. Long trips multiple times a year, kid/dog/stuff hauling. Have owned many (VW, Mercedes) and stoked to have another on the way.

Also appreciate the extended warranty discussion here, a note on those we've driven a lot of Mercedes, had a 2010 GL350 (their "big" SUV) Diesel - awesome car, bought CPO w/ Extended warranty and I estimate we had 10-12K warranty work done on it. Similar experience w/ an AMG Wagon but much less, still the extended CPO warranty was totally worth it, that roll of the dice won for us. However, M-Bs are known maintenance wh0res especially as mileage and age creep up.

Now, would I do this on the new Denali BD? Maybe, still doing the research on long(er) term ownership plus the aforementioned diesel bits that might *not* be considered warranty.

 

[Michael Lewis]

I’ve had my new Yukon with the Babymax for about a week now and and beyond thrilled with it. I was a little apprehensive but it is everything people describe and more. Averaged 30 miles per gallon on the 200 mile trip back from the dealer and I think it actually outperforms my ‘17 Yukon with the 5.3 and around town driving. Quiet, strong, efficient.

The only downside so far is that many stations with diesel around here don’t have credit card readers on the one diesel pump they have

 

[srm51475]

Guys,

I am the OP who started this thread and have been away for a while and thought I would check in and post an update on my diesel situation. Surprised to see this thread still going with so much activity, so thanks for all the input.

I started this thread in January just to ask some questions and since then completed my research and purchased a 2021 Yukon SLT White with 3.0 Duramax in June. After exhaustive searching (we know how hard they are to find), I was about to try to order one when I found exactly what I wanted coming into a dealer here on the other side of Michigan. I called and was surprised it had not been sold prior to delivery so I put my name on it immediately. Shout out to the dealer, Elhart GMC in Holland MI. They were great to work with as was the sales person. Even in this market they honored my GM employee Legacy discount. So the truck sold for that price, no haggling, no supply/demand oversticker upcharge. I paid @$63K for invoice $74K. I feel very lucky to even find this truck let alone purchase this truck for that price.

Now to my review: picked up June 13 and now have 16,000 miles and two oil changes done. (Yeah, I drive A LOT) which is why I wanted the Duramax. Simply stated, this truck is amazing and beyond my expectations, I love it! This is my first diesel so I was apprehensive, but it has been a fantastic experience. I tow a little (23ft Sea Ray) and it hauls like I don't even know the boat it there almost. However, my main purpose for getting this vehicle was mileage. Remember, I drive A LOT! So far I have consistently averaged all around driving 27.1 and on the freeway with air on driving 70-74 I have repeatedly obtained 30-33 mpg and once, under favorable conditions, was able to get 36-38 for more than a 50 mile interval. If I am on the freeway more than 30 miles (which is everyday) and I'm not over 30 mpg I wonder what is wrong. I am very impressed with these numbers, and no, I am not making this up as a diesel fanboy. This is my truthful report. I have refilled DEF 3 times in this mileage. I will say that mileage goes down significantly if I am running 75-78 mph., usually around 24 mpg.

No problems to report at all. Very satisfied. Truck is smooth, quiet, plenty of power (I'm a feather foot on gas anyway), and responsive. Rides so much better than my 2015 Tahoe LTZ which had 237,000 miles when traded in and consistently averaged 18 mpg all around driving. My 2003 Tahoe Z71 had 288,000 miles when sold it so I take care of my trucks and expect this Yukon Duramax to go even farther with proper maintenance.

I would say the Duramax has satisfied my purchase reasons extremely well. By that I mean 18 mpg in the 2015 Tahoe 5.3 vs 27 mpg in the 2021 Yukon Duramax is 50% increase in fuel efficiency. I have not calculated exact math, but even with the price differential between gas and diesel here in Michigan (currently about $3.09 gas vs $3.30 diesel, I believe I am way ahead and the diesel is doing what I bought it for.

Only negative I can say is I hate the Auto Stop feature. I haven't looked recently, but if there is now a way to permanently shut off, I will get it.

Thanks for keeping this thread going and I hope this info helps you guys.

 

[Wileybird03]

There a link in one these posts a guy had for that auto start/stop switch you can put in to get rid of the auto start/stop

 

[srm51475]

There a link in one these posts a guy had for that auto start/stop switch you can put in to get rid of the auto start/stop

I did some searching and didn't find the link you were talking about. However, I did find this https://www.autostopeliminator.com/collections/gm. a Not sure if it's the same one you were talking about, but it sounded legit, so i ordered it. Fast shipping, fairly simple install following a video on their site and so far seems to work just like they say. i've only driven up and down the street to test so no long driving to test, but seems like it does the trick. I will also post this link in the General Discussion forum.

 

[CTown Duramax]

I have a 4WD LT diesel and like it very much at 1,100 miles. I am very pleased with it and glad I got it. I find no disadvantages to having the diesel. The engine moves the big truck along in a hurry, no slouch for acceleration at all, more than enough. There's no turbo lag, none at all, for the turbo to spool up like it does with some engines. Floor the accelerator and hold on as three tons rocket ahead. You'll appreciate having so much low-end grunt. Consumption is the same as a modern V6 sedan, 20 mpg in city traffic, 27 - 29 or better hwy. I am getting 20.3 in city traffic driving. DEF gauge looks like it hasn't moved in 1,100 miles. As it gets colder, there's a two or three second delay holding the start button first thing in the morning. I let it idle a little but I don't need to. The auto stop start is no big deal. If you forget to disengage it, you can hit the off button the first time it stops. The auto-stop function too aggressive. It does not stop when you're letting it idle in the driveway or for stop signs unless you pause at a dead stop. I would not shut it off if I were in the suburbs and not in heavy city traffic. As others have mentioned, the engine has been in Chevy and GMC pick up trucks now for two years, so GM has had time to work out any kinks if there ever were any.

 

[CTown Duramax]

If your driving less than 40 miles a day, this is not the engine for you.
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The dozer will get clogged, the SCR will get clogged, DPF, DEF heater lines, and a few other things, that the warranty MIGHT not cover, as it could be considered driver negligence, or lack of maintenance.

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Hi Tollkeeper. I am interested in what you say. We are doing mixed driving w our new Durmax, a lot of hours in traffic and then a 400 mile weekend every month. I only have 1,300 miles on the odometer after today's drive, but no hint of trouble.

What are your suggestions for preventative maintenance? I would think low sulfur and fuel quality would be important. Maybe a recommended additive? What about changing the fuel filter and an oil change at shorter intervals?

BTW, what are SCR and DPF?

The Euros use 4cyl sub 120ci modern turbodiesels, even more common than gas. No problems with my friends' cars in Germany. The city taxis are all diesels there. Same w firends here who had/have Jetta and Passat diesels. All seem to prefer the diesel to gas and use their cars just like gas engine cars. Bad fuel used to be a big problem here. I am still careful to go to name brand gas stations (if that will help, maybe).

 

[Rangerdeepv]

SCR = Selective Catalytic Reduction. Fancy term for the Diesel Exhaust Fluid usage. DPF = Diesel Particulate Filter. This is the one that causes some issues as they can be finicky with 'Regen' or other emissions issues.