TÜV  (Germany)

TÜV is a prestigious motor test lab in Germany

Test Report: No. D4-TPT 351 - 051 - 86

Nature of test
Tests on a private car to investigate the effects of an addition to the motor, gear box and differential oils

Product Name: XcelPlus (while under another private label)

1. Purpose of the tests

According to the customer's instructions, the effect of "XcelPlus" when added to normally available engine and gears oils with regard to the reduction of friction losses as well as related changes in fuel consumption and exhaust gas emissions should be established.

2. Test vehicle

Manufacturer:          Ford (Germany)
Model Name:         Granada 2.3
Type:                      GU
Chassis No:             GAGFUG 39020
First Registered:       27.02.80
Max. engine power: 79 kW @ 5000 RPM

3. Tests conducted

3.1 Check of the idling setting of the engine
3.2 Fuel consumption measurement - DIN 70030 (ECE - R 15/04 Annex    9)
3.3 Coast-down on the dynamometer
3.4 Exhaust gas measurement - ECE Regulation 15/04

4. Measuring equipment and test devices

4.1 Motor tester from Robert Bosch: Compact Test motor tester MOT 500  ignition oscilloscope MOT 400 report printer PDR 100 pressure and vacuum tester ETT 007.01

4.2 Dynamometer from Schenck: Type 500 / GS 60

4.3 Exhaust gas analyser: Horiba CVS - 61 2

4.4 CO measuring device: ULTRAMAT 13 P with NDIR analysors

5. Procedures carried out on the test vehicle

To establish the original values, all the tests listed under (3) above were first carried out with the original oils still in the vehicle. The engine settings as idle were found to be in accordance with the manufacturer's specifications (Motor Data)

Following this, the engine, gear box and differential oils were replaced with oils to which XcelPlus was added according to the manufacturer's instructions.

Engine oil: 3.50 L Valvoline All Climate 10 W 40 + 0.75 L XcelPlus

Gear box: 1.50 L Castrol EP 80 + 0.50 L XcelPlus

Differential: 1.30 L Castrol Hypoy 90 + 0.50 L XcelPlus

After a running - in period of about 2,750 km, all tests listed under (3) above were repeated.

To avoid as far as possible external factors influencing the test series, as far as possible the tests were conducted with the same engine settings, with adjustments being made as necessary. Also, new oil and air filters and new spark plugs were fitted, and the engine idling speed was set back before the start of the second series of tests from 900 RPM to 800 RPM.

For the duration of the tests the bonnet was plumbed, and the oil filler holes were sealed with sealing paint.

After running about 1,500 km of the running-in period had elapsed, about 0.6 L of motor oil was needed to top up; after the further 1,250 km a further 0.3 L was required. The seals were on both occasions found to be undamaged.

In spite of extensive elimination of factors which could have lead to a distortion of test results, the figures in (6) below include the inevitable spread resulting from the practical tolerances present in the test drives and their measurement. The figures in (6) can therefore, because of the lack of statistical certainty involved, not be taken as absolute. However, the possible spread in the measurements is smaller than the computed changes which were established during the second series of tests.

6. Test results


Base  Values

After Values



Normal Oil

+ XcelPlus


Odometer (km)




Engine Idling Settings




Idle speed (RPM)




Motor Oil Temp (ºC)




CO Concentration (Vol %)



-4.4 %

Fuel Consumption (L/100 km)




City Cycle



-4.96 %

90 km/h



-5.24 %

120 km/h



-3.73 %

Average (DIN 70030)



-4.7 %

Time To Coast Down (average N=2) seconds



+19.1 %

Exhaust Values: ECE Test (average N=2)




CO (g/test)



+16.0 %

HC (g/test)



-3.7 %

NOx (g/test)



-19.8 %

HC + NOx (g/test)



-9.8 %

7. Summary of results

The reduction of the frictional losses in the test vehicle are evidenced most clearly by the considerably longer coast - down time (19.1 %) on the test rig. They gave an improvement in fuel consumption of 4.7 % in the ECE mix. The changes in the exhaust gas emissions come less from the use of XcelPlus than from the vehicle and / or motor settings. They fall more or less within the scatter area expected in such measurements. However, the reduction in Nitrous Oxides emissions can be attributed - at least by inference - to the lower frictional losses in the engine through the use of XcelPlus.
There were further tests made, beyond the main scope of this report, which brought no negative results; among these were for example, an investigation for possible fluorine or other acidic combinations in the XcelPlus treated engine and the gear - box oils, and in the exhaust gases which could have been undesirable for the environment or for the vehicle.

When the spark plugs were changed before each series of tests, the compression of the cylinders was measured. While the peripheral measurements - such as the battery voltage were not made, which would have allowed an unrestricted confirmation of the readings taken, the improvement measured - about 7.5 psi per cylinder - infers an improvement in the sealing of the cylinders 

In summary, it is confirmed that the test described above under sections 3-6 showed a measurable reduction in the frictional losses of the test vehicle through the addition of XcelPlus to the engine, gear box and back axle oils. No negative effects resulted from the treatment.