Some oil consumption is by design

[Ty88]

From AI below. Are our LT4 blackwings intentionally designed to burn some oil. My 2026 with 6,500 miles burns about a quart every 4,000 miles.


some engines are designed to consume oil as part of their normal operation
. While most drivers expect to never add oil between changes, many modern and high-performance engines include design trade-offs that intentionally allow small amounts of oil to burn.

www.kamphausautocare.com +3



Engines Designed to Consume Oil
Some specific engine types require oil consumption to function correctly:

• Rotary (Wankel) Engines: These engines, famously used in Mazda RX models, are designed with an oil injection pump that specifically drips oil into the rotor chamber to lubricate critical seals.
• Two-Stroke Engines: Common in small tools and some older motorcycles, these require oil to be mixed directly with fuel to lubricate the crankcase as it passes through, meaning they burn oil by definition.

Modern Design Trade-offs
In standard piston engines, manufacturers often accept oil consumption to achieve other goals:

• Fuel Efficiency (Low-Tension Rings): To reduce internal friction and meet fuel economy standards, some modern engines use thinner "low-tension" piston rings. These rings don't scrape the cylinder walls as aggressively, allowing a tiny film of oil to remain and burn off during combustion.
• Turbocharged Systems: Turbos operate at extremely high speeds and temperatures, requiring constant oil lubrication. It is considered standard for small amounts of oil to slip past turbo seals into the intake or exhaust.
• Tight Tolerances & Break-in: Modern high-precision parts may allow slight oil consumption during the initial "break-in" period as components settle into place.
• Cylinder Wall Honing: Cylinder walls often have a "crosshatch" pattern. This texture is designed to trap and hold a thin layer of oil to ensure the rings are always lubricated, some of which inevitably burns.

What is Considered "Normal"?
Manufacturer guidelines for "acceptable" oil consumption can vary significantly:

• Standard Passenger Cars: Many manufacturers, including Ford and General Motors, state that consuming one quart every 1,000 to 2,000 miles is within normal operating range.
• High-Performance Vehicles: Some performance models from brands like BMW, Audi, or Subaru may consume more than a quart every 1,000 miles during aggressive driving or under heavy load.

 

[matt6060]

Just got mine back from the dealer after 3 oil consumption tests. They say GM calls this normal. I go through ~qt every 1000-1400 miles. 10800 miles total on the 2025 CT4V BW 6M. No visible leaks. They ran fluorescent dye through the last test and say they found nothing. Anyone else have the same thing going on?

 

[dribs15]

 

[Super Saloon]

Just got mine back from the dealer after 3 oil consumption tests. They say GM calls this normal. I go through ~qt every 1000-1400 miles. 10800 miles total on the 2025 CT4V BW 6M. No visible leaks. They ran fluorescent dye through the last test and say they found nothing. Anyone else have the same thing going on?

This does not sound normal for the LF4 CT4V BW. Mine has just under 13K miles and I have never added any oil between changes. Your post prompted me to check and I am still full from the last change, which was 3,500 miles ago. Are you tracking the car a lot? That I think would be an explanation, otherwise it sounds like something is off.

 

[1Evil55]

Other than a few runs down the 1/4 mile I've never tracked any of my BW's. I've also never needed to add oil. Small amounts are understandable with these motors. Quart's doesn't sound right.

 

[matt6060]

This does not sound normal for the LF4 CT4V BW. Mine has just under 13K miles and I have never added any oil between changes. Your post prompted me to check and I am still full from the last change, which was 3,500 miles ago. Are you tracking the car a lot? That I think would be an explanation, otherwise it sounds like something is off.

I'm escalating the issue to GM.