LM2 Break In?

[Capsaicin]

Approximately how long does it take for the Lm2 Duramax to break in. I've heard it can take about 2k miles for the compression to build before you see better MPGs and power. Does that sound right?

Also what is the best way to drive the Tahoe w/ the Lm2 to maximize efficiency?

 

[Stbentoak]

Uh …I don’t think so….
On my previous eco-diesel FCA unit they said it would be at least 40,000 miles to be fully broken in, unless you towed frequently. Then it could possibly be reduced to 20,000. These are long-term built engines, let’s just say they are 300,000 mile engines, it certainly wouldn’t be uncommon to take 10% of that to break in fully…

 

[Wileybird03]

Just drive it like you normally would‍ All I ever do!!

 

[steiny93]

Neither of these engine have any noticeable mileage change (I have both) based on break in. They both have the typical vary the engine rpm and load for first 500 miles deal.
Who at FCA said it takes at least 40k miles to 'break in' an ecoDiesel? They must be building their cylinder walls and rings out of something they pulled off a comet

Seriously tho, none of these motors are 'breaking in' after a tank of diesel or two, those rings are seated. If they weren't you'd have oil consumption and engine block pressure issues like crazy.

 

[Yukon21Denali]

It’s never about engine break in… engines are properly broken in as part of assembly process in the factory. Go easy for first 1500 miles is about overall drivetrain and also operator to get good handle on the vehicle.
Topic of discussion ad nauseam in corvette forum.

 

[Stbentoak]

It’s never about engine break in… engines are properly broken in as part of assembly process in the factory. Go easy for first 1500 miles is about overall drivetrain and also operator to get good handle on the vehicle.
Topic of discussion ad nauseam in corvette forum.

Sorry, but diesels are different…..takes a good while to get full efficiency from them…..

 

[CTown Duramax]

I noticed a 10% jump in mpg btw about 3,500-5,000 miles.

 

[Capsaicin]

I noticed a 10% jump in mpg btw about 3,500-5,000 miles.

First tank was 22.6 mpg. Just filled, 24.9 mpg. Only 2k miles on her.

 

[booyaltz]

Best way to drive it for efficiency? Drive 35-55mph on flat roads, slow accelerations, coast into stop lights/signs, and keep the auto start/stop feature activated.

 

[Capsaicin]

I averaged nearly 28 mph on a family trip from the Nashville area to Eureka Springs, AR. Lots of highways and mountain roads.

 

[CTown Duramax]

That sounds about right to me for fast driving over East Coast elevations.

 

[steiny93]

Sorry, but diesels are different…..takes a good while to get full efficiency from them…..

Please explain how diesels are different

 

[Stbentoak]

Both engines are "broken in" in about 150 hours on the meter. But as diesels wear in the cylinder walls over a much longer time, their efficiency improves, and they start attaining their best economy and pulling power around 30-50K miles depending on how hard you have worked them. Diesel engine life expectancy is much higher than a gas engine (Sans emissions controls). A million-mile diesel engine is not all that uncommon. 50K miles on a diesel engine is like 10K on a gas engine....The more it runs the better it likes it...

 

[CTown Duramax]

One thing I noticed driving BMW B48, Benz 220D and Audi 40 TD four cylinder turbo diesels on German roads is that they are noticeably slower to accelerate at high speeds - say over 100 mph - BUT, those cars still made it to an indicated 235-240 kph, almost 150mph.

At our speeds, 80 - 90 mph, it won't make much of a difference to notice.

This in line turbo six has plenty of get up and go. I wish GM would build a big sedan around this engine and platform, like a Roadmaster or DeVille.

 

[steiny93]

But as diesels wear in the cylinder walls over a much longer time, their efficiency improves, and they start attaining their best economy and pulling power around 30-50K miles depending on how hard you have worked them

I completely disagree, but it's all good, I like people thinking machines get better over time.

 

[OBSSSD]

Approximately how long does it take for the Lm2 Duramax to break in. I've heard it can take about 2k miles for the compression to build before you see better MPGs and power. Does that sound right?

Also what is the best way to drive the Tahoe w/ the Lm2 to maximize efficiency?

My mpg was great brand new, maybe another 1mpg after 1,000 miles but near no change