2021 test5 productsMyths & Experiments
Which Diesel Fuel Alternative Brand Wins?
A head-to-head test of 5 diesel fuel alternative options with the measured results for each. See how they ranked and watch the full test video.
Ranked first
diesel summer grade (control)
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The measured results
Every number below is read straight from the test. Scroll sideways to see all measurements. Products are listed in the order they finished.
| Product | Engine Run Test | Lubricity Test | Cold Temperature Test | Corrosion Resistance Test | Manufacturer Claims |
|---|---|---|---|---|---|
| 1diesel summer grade (control) | used as the baseline fuel; engine ran normally | 425 W friction reading, the worst (highest friction/largest wear scar) of all five fuels tested; used as the baseline for the wear-scar percentage comparisons | just about reached its cloud point in the 0 F freezer test (did not fully gel/freeze) | rust level very close to the uncoated control sample, one of the two worst results (with biodiesel) for corrosion resistance | not tested |
| 2biodiesel homemade, from vegetable oil, methanol, and potassium hydroxide | ran the engine well; exhaust smoke had a noticeably better smell than diesel exhaust | around 405 W friction reading, with a wear scar 21% smaller than diesel, the best result of the diesel/hydro diesel/biodiesel trio, though still worse overall than vegetable oil and used motor oil | gelled in the 0 F freezer test | rust level very close to the control sample, one of the two worst results (with diesel) for corrosion resistance | not tested |
| 3vegetable oil straight, unmodified | ran the engine well, described as running just as good as on diesel and biodiesel, with great throttle response | 365 W friction reading, the lowest (best/least friction) of all five fuels tested; vegetable oil and used motor oil together provided better film strength than diesel, hydro diesel, and biodiesel | froze solid in the 0 F freezer test, the only fuel of the five to fully freeze; host notes it needs to be heated for use in sub-freezing temperatures | third best (of five) for corrosion resistance | not tested |
| 4hydro diesel emulsified water/diesel blend, sent by a viewer (Matt, Warped Perception YouTube channel) | the only fuel the engine struggled with, producing quite a bit more smoke than diesel or biodiesel; running the engine on plain diesel afterward was needed to clear the smoke | around 410 W friction reading, with a wear scar about 5% smaller than diesel | did not freeze in the 0 F freezer test, the best cold-weather result of the five fuels | the BEST (least rust) of all five fuels tested, which the host said surprised him | claimed to burn cleaner and offer better fuel efficiency via a stable water-in-diesel emulsion |
| 5used motor oil old 5W-30 (~4,000 miles of use), cut 1 part gasoline to 10 parts oil | ran the engine surprisingly well, much better than the host expected, with great throttle response and only a light smoky haze | around 370 W friction reading, close to vegetable oil; together with vegetable oil, provided the best film strength of all five fuels tested | not tested | second best (of five) for corrosion resistance, behind hydro diesel | not tested |
How it was tested
- engine run test on each fuel type
- lubricity / film strength wear-scar test
- cold temperature freeze/gel test (~0 F)
- corrosion resistance test (hydrogen peroxide, vinegar, and salt exposure)
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