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.

 

[Neveready]

I'm escalating the issue to GM.

How did that call go?

 

[matt6060]

GM referred me to a different dealer. I'm doing another oil consumption test with them but they are saying 1qt every ~1000 mi is normal as well. I've contacted a lemon law attorney.

 

[blkout]

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.
View attachment 33765www.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.

My 2024 CT5-V BW has 11K miles and doesn't use any oil at all. While GM might consider some oil usage normal, all that tells me that they're allowing for some manufacturing intolerances or improper break-in by the owner so they don't have to warranty every engine that uses any oil. A properly functioning engine should not use any significant amount of oil. This is my second LT4 engine car, my first was a 2021 Camaro ZL1, I owned that car for 4 years and it never used any oil either.

 

[Kawman]

I can also report no measurable oil usage on the street or the track. I'm at 17K and have never added oil.

But, .. my last car is a 2001 BMW M5. I got the car 35 months old with 35K miles. It now has 260K miles and has steady burned 1 qt of oil every 1K miles all of it's life.

 

[ngoni]

11k miles and zero consumption whatsoever. However, this thread has reminded me to go check my oil level. It's been a while. I got spoiled with the digital dipstick in my old beat up BMW.

 

[NewCaddy]

I thought GM has a bulletin out on this subject where 1 qt in 2,000 mi is acceptable.

 

[thefleshrocket]

I checked mine after a few thousand miles and one track day, and it was about halfway down the hash marks between full and add, so apparently it's drinking a little bit of oil. But nowhere near a quart every thousand miles. Even my 2011 Audi S4, which has a supercharged 3L V6 that known for being thirsty, typically only goes through a quart every 2000-2500 miles. That motor has about 100K on it, the chassis about 155K.

 

[matt6060]

Ok so last week I elevated to GM customer service. They referenced me to another GM dealer (Chevy). Doing another oil consumption test with them. They are also saying 1 qt per 1000 miles is normal. I hated to do this but I contacted a lemon law atty. I really love this car but I cant take a gamble on such an expensive purchase.

 

[blkout]

Ok so last week I elevated to GM customer service. They referenced me to another GM dealer (Chevy). Doing another oil consumption test with them. They are also saying 1 qt per 1000 miles is normal. I hated to do this but I contacted a lemon law atty. I really love this car but I cant take a gamble on such an expensive purchase.

I don't think the engine is going to fail any sooner because it uses oil, however I would find it very annoying to have to keep checking the oil constantly and adding oil knowing that I shouldn't have to.