[1]Where did the oil go?
Consumer Reports [2] published an article this summer that exposed higher oil consumption [3] between oil changes in higher miles-per-gallon late-model autos. The article basically identified the trend of higher oil consumption to the new higher miles-per-gallon engines. In one case the writer identified a vehicle that used a quart of oil every 1,200 miles.
Digging deeper, Consumer Reports pointed to the lightweight “0-weight oils that are prevalent in performance engines.
Our friends at Driven Racing Oil [4] really got to the nuts and bolts of oil consumption in late model, high MPG engines, then published a bulletin explaining the how and why of this oil usage.
Bottom line – evaporation is the culprit.
According to Driven Racing Oil, “The reasons for this consumption are not mechanical, such as stuck rings or loose clearances. The reason for this “vanishing oil” is due to a technical term that also starts with a “v”—volatility.”
A liquid is considered volatile when it can evaporate by converting to a gas or vapor. Almost all liquids have a temperature where they begin to volatilize. Driven’s oil consumption bulletin points out that “Not all oils evaporate at the same rate. Typically, motor oils featuring lighter base oils evaporate more quickly at high oil temperatures.”
To many muscle car owners, it’s going to come down to how much oil is vaporized vs the amount of performance felt at the seat of the pants.
For more information on oil consumption and usage, read Driven Racing Oil’s bulletin by clicking here [5].