Dynamic Fuel Management - How it Affects Your Transmission

fatwhiteboy · December 28, 2019

On 12/26/2019 at 8:57 AM, gmcsierra71 said:
A Look at the New Dynamic Fuel Management System and How it Affects Your Transmission

https://gearsmagazine.com/magazine/sipping-fuel/
https://gearsmagazine.com/magazine/sipping-fuel/

Thank you for the link. Great info, I bookmarked it.

gmcsierra71 · December 28, 2019

In addition to Dynamic Fuel Management effects on transmission, this article also recommends oil change frequency. this article states "Like the AFM/DOD system, you will hear me preaching about the importance of using the correct engine oil and filter along with the need to change it often."

In a previous article I posted

GM Escalates Cylinder Deactivation With Dynamic Fuel Management

https://www.chevyhardcore.com/tech-stories/engine/gm-escalates-cylinder-deactivation-with-dynamic-fuel-management/

This article stated "Current AFM engine issues appear to revolve around problems stemming from lifter failures, which can be traced to infrequent oil changes."

The service manager at my local GMC dealership suggested to me " do not go by the DIC Oil Life Monitor and let it get close to "0" before changing the oil". He didn't recommend a mileage number, but recommended changing the oil sooner than the DIC suggested.

The local shop that services my truck for oil changes also recommends "frequent oil changes". I have read other articles that state " clean oil helps with the longevity of AFM engines".

Moend · December 29, 2019

Using synthetic oil can get you 10k probably. Now the on board computer uses lots of things to determine the time to change the oil which seems to be roughly 7500 unless you are using tow haul or long idle time. All in all mine seems to always line up with the 7500 mark. Interestingly this is the recommended miles to change if you forget to reset the EOL.

For average people they will put 15k on their vehicles a year which mean you will have to change the oil twice I chose to change it 3 times. Its an extra $50 dollars a year and like other folks had mentioned its a low price to pay for a piece of mind.

The unsettling thing in this article is that a malfunctioning engine will cause transmission issues - that is a weak design if its true. There should be a fail safe condition if/when the engine performance is compromised, to protect the transmission even if it meant reduced overall performance or entering limp home mode. I understand some of the engineering choices are dictated by higher power (management and finance). But I think this one shouldn't.

fatwhiteboy · December 29, 2019

Call me old and/or a pessimistic, if it was an option, I would opt out of any cylinder deactivation and definitely opt out of stop start. Even at best if you see 3 or 4 MPG increase any fuel savings will be eaten up in repairs down the road. I will not purchase a vehicle that does not have a stop start defeat button. In all reality if a person buys a ½ ton truck and wants good gas mileage they really should be looking at the 3L diesel. And if gas mileage is a priority possibly another vehicle than a truck. This is not about making the consumer happy, it is about making GM’s fleet average up meet the upcoming CAFÉ standards. So every 1/10 of an MPG counts more to them then us.