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Jul
12
Taxi Fleet Test

Fleet Test Part I

Taxi tests, six cars, all Ford Crown Victorias

The point of this test is to see if Auto-Rx is worth the cost of the product and taking the time to add it at every PM (preventive maintenance).

Notes on Tests:
All cars were driven by taxi drivers in regular service in good weather. Mileage was tested and hand calculated at the start and compared with ScanGauge readings. The ScanGauge was used for all future readings. The errors were consistent; that is, if it was 4% off, it was 4% off on every tank for a given vehicle. Error rates ranged from 2% high to 7% high for different gauges on different cars and since this test looks for trends, not absolute values, because we were using different vehicles the ScanGauge readings were accepted. One thing in our favor is that the same driver always drove the same car.

All vehicles were serviced every 3,000 miles and conventional 5w-30 oil was used. Each car was driven for 500 miles to get a base line for mileage and then the testing began.

Vehicles

  • Vehicles 1 & 2 received Auto-Rx

  • and the driver was aware of the test.

  • Vehicle 3 driver was aware of the mileage test but was told we were testing mileage with different tire pressure settings but did receive Auto-Rx.

  • Vehicle 4 driver was aware of test but we used an engine flush.

  • Vehicle 5 driver was aware of a test but also was told it was a mileage test with different tire pressures. This was also an engine flush car.

  • Vehicle 6 driver was aware of the test but was again told it was a tire pressure test and received a gas additive which was actually regular unleaded gasoline with a blue dye.

All vehicles were run with 40psi, which is the usual pressure for the fleet.

Mileage varied a great deal between cars and is the result of very different driving styles. All vehicles improved their mileage numbers when the test began over the first four thanks of fuel. At the beginning the worst was 11 mpg and the best was 16 mpg during the 500 mile pretest run. The average improvement over four tanks was 3% from the actual start of testing.

The ScanGauge readings for gallons per hour at idle were recorded and all vehicles read .5 to .8 gph.

All cars were in good working order with odometer readings from 180k to 455k. The 80k vehicle was considered a new car by the drivers and the 455k an average vehicle that would be kept until its first major accident. Other than accidents, these Crown Victorias are kept until about 550k miles before being parked and used for parts. They are
only put out at about 550 because there are rules about not using cars over 10 years old.

The point of this test is to see if Auto-Rx is worth the cost of the product and taking the time to add it at every PM (preventive maintenance).

Vehicles 1, 2, and 3 received 20 ounces of Auto-Rx and then 4 ounces at every 3k oil change.

Fleet Taxi Test Part II

The taxi fleet test data has been extended out over a few more OCIs [oil change intervals]. Also, another test Cab #8 was changed over from a Lucas oil additive to Auto-Rx at the 15,000 mile mark. The results speak for themselves.

Results focused on gas mileage. Empty cells indicate mileage not achieved yet or not reported. Mileage is averaged over as close to 50 gallons starting on the first fill-up after the PM.

Veh#
0K
3K
6K
9K
12K
15k
18k
21k
24k
27k
30k
33k
36k
1
15
17
19
19
18
18
18
17
17
18
18
18
18
2
13
16
17
17
17
15
18
18
17
18
16
18
3
14
15
15
16
16
15
14
15
15
15
15
15
4
15
15
15
14
14
11
14
15
15
13
12
15
15
5
12
12
12
13
13
11
12
12
13
10
11
11
13
6
15
15
15
16
16
14
16
13
15
16
15
14

Two vehicles (7 and 8) were added. Both vehicles received a Lucas oil additive at every oil change on the same PM schedule at 3k intervals.

Please note that at 15k miles on Vehicle 8, Auto-Rx was installed, and Lucas was discontinued. Notice the improvement.

Veh#
0K
3K
6K
9K
12K
15k
18k
21k
24k
27k
30k
33k
36k
7
12
11
12
10
11
12
12
10
9
10
11
12
10
8
14
15
15
14
13
13
15
15
16
16
16
17
16

Again, a ScanGauge was used in each vehicle. The readings were all off to some degree but consistent (that is, repeatable) and show trends, which is what we are looking for.

The maintenance dose was 4 ounces because these vehicles are in severe service and were a bit sludged up at the start of the testing. Otherwise, 3 ounces would have been used.

Vehicles 1 and 2 showed the only significant increase in gas mileage. Compression figures are coming. I just have not collected them all from the four mechanics that worked on these vehicles.

A reminder about the vehicles:

Vehicle #1: Driver aware of Auto-Rxadded.
Vehicle #2: Same as 1
Vehicle # 3: No Auto-Rx
Vehicle # 4: No Auto-Rx, flush used
Vehicle #5: No Auto-Rx, flush used
Vehicle #6: No Auto-Rx, fake gas additive
Vehicle #7: No Auto-Rx, Lucas every 3k miles
Vehicle #8: No Auto-Rx, Lucas every 3k miles; Lucas stopped after 12k miles, and Auto-Rx installed at 13k miles.

Fleet Taxi Test Clarification

NOTE: This information is posted here to clarify the discrepancy as to whether Vehicle 3 actually received Auto-Rx.

Hello, all. Im Larry, the guy that did this long-run test. Im here to answer any questions that I can. The problem with #3 was that the car was pulled from service and a new one replaced it. There was so much data to go through that I messed up #3.

Overall, the drivers picked were those known to be serious cab drivers that did not abuse their cars. All cars were driven by the same driver, no sharing. They kept the car 24 hours a day, 7 days a week. I drove one of the cabs for various amounts of time, which I guess breaks the one-driver rule for one car, sort of. I even got a hack license and all that legal stuff. It was quite an experience.

All cars were Crown Vics that were [former] police cars. A new car to a cab driver is one with about 100k miles on it. The mileage on these cars ranged from 92K to 540k miles. They are tough vehicles. When a car hits the end of its life, it may be kept for parts or sold off to Mexico. Most cars make it to a graceful end, but a few, very few, get destroyed in accidents. They range from 1989s to 2004s. No one would tell me what the pay for these cars as they are purchased in batches of 10 to 15, where they take every car in the batch. Once in a while one goes straight to the back lot for parts. The cars spanned two different cab companies with different owners.

There were some comments Id like to make. Most of the cars smoked a little, very small amount, usually on startup, and a couple of them smoked when slowing down after a run on the freeway for an off ramp. The Auto-Rx cars stopped smoking in as little as 6K miles. The flushed cars showed no sign of diminished smoke. The Auto-Rx cars also kept the plugs cleaner.

A comment about flushing. It produced gunky looking oil for sure on the oil change after a dose but did nothing that we could see in the area of improved compression, mileage, or reduction of the small amount of oil smoke. Im just not sure what flushing does for an engine that is in pretty good shape. I think that Auto-Rx has the right stuff and this slow cleaning does the job.

One other comment. A Crown Vic that is used to transport people that have been arrested by the police to the local jail was tested with Auto-Rx. When they arrive at the seen of an arrest, they are left idling. Often a prisoner is placed in the back and locked in while the work at the arrest scene is completed. Oftentimes, this is an hour or more, sometimes as little as 15 minutes. These cars are often placed on weekends where they are expected to be needed. The mileage is very low and the maintenance plans for these vehicles include uncertain oil change intervals.

This test ran for six months with 3,588 total miles added to the vehicle. The fuel usage records and logbooks show that this vehicles engine must have run at idle for long periods. It used 522 gallons of gas when one would expect for driving alone it would use about 200 gallons of gas. The comment that Im getting to is that the test was prompted by the fact that this vehicle failed smog before Auto-Rx and passed after 6 months. The vehicle came very close to passing but did fail after 2 retests. The delay in retest was granted to allow time to repair the vehicle. No repair was done other than the Auto-Rx.

Also the mechanic stated that the plugs were changed at the start of the test and looked like new at the end. He made the comment because plugs in other similar vehicles were often replaced during similar intervals of service under the same conditions. This vehicle was also driven a bit more and had its oil changed at the beginning of the test with Auto-Rx added, 20 ounces. It was then changed at 200 gallons of gas and 3 ounces added for the next 200 gallons and this interval has been continued. At the end of the test, this vehicle had burned 700 gallons of gas and was in its 4th oil change interval. The increased driving also helped to allow the Auto-Rx to do its work inside the engine.

My suggestion for oil change intervals for such vehicles has been adopted, that is change the oil at 200 gallons of gas used. At the start of the test, this vehicle used .4 to .6 gallon per hour depending on the weather and electrical load. At the end of the test, it used between .4 to .5 gallons per hour, a small but useful improvement.

This test does not prove that Auto-Rx will allow your engine to pass a smog test but does show that Auto-Rx did help improve the operation of this engine in a useful way that the maintenance people could actually see. Its possible that the oil change interval based on fuel used might receive favorable consideration by other maintenance groups.