A few newbie diesel questions

[corrupt]

Hi all,

My 2025 Tahoe HC with the LZ0 just arrived. I've never had a diesel before, so forgive me for asking such basic questions.

Is it a good idea to start the truck for a couple minutes before driving it? Does it depend on the outside temperature?

Should I consider using any fuel additives? If so, how often should I use them and which should I use? I don't have any "top tier" diesel available in my area -- but I do make sure to use high traffic stations that turnover their diesel regularly.

Should fuel mileage improve as the engine is broken in? I'm seeing pretty good milage on the highway (25-30mpg) and so-so mileage (although still better than my old 5.3L) with just city driving (15-17mpg). This may be perfectly normal, not sure yet.

I know about regular oil changes, fuel filter changes, etc -- any other standard maintenance or general do's and dont's that I should be aware of?

Thanks!

 

[DuraYuk]

Congrats!
Drive it like a normal gas machine.
No additives. Its snake oil.

Gas mileage will improve as it breaks in. We get about 22 city and 30hwy average.

If you live in arctic temps than some care will need to be taken in terms of block heating and anti gel for fuel. But we are talking extremes there.

Fuel filter is really the only thing you do more often than a typical gas engine. Its super easy to do on these and you can do it yourself.

 

[steiny93]

Regarding startup and cooldown, treat it like any other engine. At first startup (say first 5 min), be reasonable as it's coming up to operating temperature. If it's really cold (say -10F or below) I let them idle for a minute or 2 before moving.

I don't use any additives, fill up at high volume stations and keep on top of the fuel filter change cycle.
In the winter if you get below 0F make sure you are getting winter blend fuel.

I follow the dash for interval for both engine oil and fuel filter.

I'm seeing similar highway mileage (30ish when on 60mph roads, 25ish when on interstate), in town seeing 18-19mpg.

Make sure you don't accidentally get DEF or gasoline into the diesel tank (sounds silly but happens).

 

[StephenPT]

Just drive it. This engine was designed to be short tripped, long tripped and anything between. It's not a fussy engine when it comes to cold start or regen cycles.

I don't think it's necessary for everyone, but I personally installed a Banks IDash so I can watch regen cycles, oil temp and a few other data points. Watching the regen cycle allows me to know when it's doing a regen and I make sure to finish it before pulling in the driveway and turning it off. I'd say after almost three years I've had no more than 3 times where I took the long way home so I could let it finish the regen. If it doesn't finish the regen it will start it on the next drive cycle. If you go too many drive cycles without completing the regen a message will pop up and say "Continue driving to clean exhaust filter."

The LZ0 puts out more power than the LM2, so I don't think it will see the same fuel economy as the LM2. Maybe a 2-5% difference, but time will tell. You should still see low 30's on the highway if you keep your speed below 70mph.

 

[ZKWBQD]

Hi all,

My 2025 Tahoe HC with the LZ0 just arrived. I've never had a diesel before, so forgive me for asking such basic questions.

Is it a good idea to start the truck for a couple minutes before driving it? Does it depend on the outside temperature?

Should I consider using any fuel additives? If so, how often should I use them and which should I use? I don't have any "top tier" diesel available in my area -- but I do make sure to use high traffic stations that turnover their diesel regularly.

Should fuel mileage improve as the engine is broken in? I'm seeing pretty good milage on the highway (25-30mpg) and so-so mileage (although still better than my old 5.3L) with just city driving (15-17mpg). This may be perfectly normal, not sure yet.

I know about regular oil changes, fuel filter changes, etc -- any other standard maintenance or general do's and dont's that I should be aware of?

Thanks!

You should be doing all of those things. But to give you the truth, sell the diesel, and buy gasoline power.

 

[dc968]

You should be doing all of those things. But to give you the truth, sell the diesel, and buy gasoline power.

Why would you say that?

 

[LEsoftballdad]

I disagree on fuel additives. They are absolutely necessary, especially with the advent of ultra-low sulfur diesel. An additive, such as Archoil, will add lubricity to the fuel. Watch the Freedom Worx video that shows what it can do for your engine.

 

[Stbentoak]

All additives do are drive your cost per mile up. They may make you feel good and certainly these places make a ton of money off of it. I've had multiple diesel vehicles over the last 20 plus years, never used any of it other than power service in the winter on a 5.9 Cummins. Changed my fuel filters regularly, and never had one fuel related issue.

 

[Silverado4x4]

As said no additives are needed that guy is just trying to sell his product. I had a 05 lly Duramax 2500HD and never ran additives just run it. Even the owners manual says dont not use additives. Run it just like a gas motor with the exception of changing the fuel filter and use a high volume station that sells Diesel and stay away from those small mom&pop filling stations.