I'm planning to test an engine oil additive that appears to have some solid science behind it. But before running the test, I wanted to run the protocol by so folks can comment on the goals and specifics:
- Flush oil change - dilute the undrained oil in a change by doing two, oil changes with a warm-up drive in between. Use quantity measurments and oil testing to calculate the amount of oil not drained.
- Use engine idle fuel consumption to measure change in friction - by measuring how much fuel is burned to sustain a given idle rpm, we'll have a metric to calcualte the increase or decrease in engine energy loss from just the oil change compared to the oil change with additive.
So the detailed steps follow:
- one tank gasoline - all tests are run using the same gasoline in the fuel tank. No other changes to the vehicle.
- baseline warm idle fuel consumption - with the car in "N", warmed up for over 20 minutes, measure the fuel consumption in idle for at least 10 minutes. I'll use AutoEnginuity to record the mass flow, ICE rpm and coolant temperature.
- baseline cold-to-warm fuel consumption - start the car after a cold-soak with AutoEnginuity running. Monitor mass flow, ICE rpm and coolant temperature. However, once the ICE starts, the car tries to recharge the traction battery. I'll defeat that by shifting into "N" and let the car run for at least 10 minutes. I will compare the fuel consumption vs. ICE temperature values to see if we can use just this metric to also cover the warm-up metrics.
- old oil change and sample - I'll drain and measure the used oil including filter and keep a used oil sample, #2, to send for analysis. I'll also save a reference sample, #1. I have always used Mobil 1 and have a case of 5W-30, the recommended oil. I will then drive the car for 50-100 miles including high speed to throughly dilute any residual oil from the change.
- flush oil change and sample - this change will also include the oil filter. The goal of this change is to establish a baseline for the new oil as close to the 'out of the bottle' value as is practical. The sample, #3, will include any residual oil not drained in the change. We will measure the amount of oil drained.
- baseline new oil idle hot and cold - same as the first two tests, the goal is to measure the fuel consumption at idle and the warm-up profile. This establishes the best-case, new oil baseline.
- apply additive - drive 50-100 miles to mix and allow it to work as expected.
- run the warm and cold fuel consumption tests.
- 1,500 mile change - the vendor claims varnish can be suspected by their additive and recommends an oil filter change. Another sample, #4, for oil analysis since it is just as easy to change the oil and filter and top off the additive.
So as a result of this protocol, we should have:
- Virgin oil analysis - used to measure offsets of the following oils and includes the quantity added.
- Used oil - establishes what was in the engine before the test including the quantity.
- Flushed oil - used to do partial fractions to estimate how much of the old oil remained after the first change. This includes the amount drained and added.
- 1.5k sample - used to measure any 'varnish' or other changes in the oil as a result of the additive.
Now I may decide to use just the ICE warm-up data record. It starts cold and progresses to warm. However, warmed up engines can be significantly warmer. I'll use the early metrics to decide.
I'm interested in making sure the test protocol is as free from bias as possible and sensitive enough to identify the additive effects. So using engine idle, fuel consumption, we have a stable, reproducible configuration, in which engine friction is a significant power drain. Leaving the engine in "N" ensures no traction battery power flows in or out.
Thanks,
Bob Wilson