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EVP Fuel Requirements for All Tuning
The fuel each EVP tune needs: pump gas octane and how to mix 93 and 95, fuels for 100 octane tunes, and which E85 is safe for big turbo tunes.
Fuel is a critical part of enjoying your EVP-tuned vehicle. Some customers may be under the impression that all fuels are roughly the same. This page explains the differences between fuels, to save you from costly repairs caused by poor fuel or an octane rating too low for your tune.
Pump gas tunes
Each of our 91 and 93 octane tunes has been validated on non-oxygenated pump fuel at the required octane rating. We use non-oxygenated fuel because blended fuels have a short shelf life, and there's no way of knowing how old the fuel that comes out of the pump is. Even so, we build plenty of margin into each tune to account for 91 octane pump fuel, whether oxygenated or not.
Do not use 87, 89 or 90 octane under any circumstances.
We don't recommend octane boosters to reach the octane rating you need: their quality varies widely between brands, and some of their claims are outlandish.
You can make 93 and 95 octane by mixing 91 octane fuel with either 100LL (available at most airports) or VP 110. For 10 gallons:
| Octane | With 100LL | With VP 110 |
|---|---|---|
| 93 | 2 gal 100LL + 8 gal 91 octane | 1 gal VP 110 + 9 gal 91 octane |
| 95 | 4.5 gal 100LL + 5.5 gal 91 octane | 2 gal VP 110 + 8 gal 91 octane |
100 octane tunes
Several fuels can be used:
- VP UTV 96 (actually 98.8 octane, but safe to use with EVP 100 octane tunes)
- 100LL (avgas)
- A mix of VP 110 and 91 octane: for 10 gallons of 100 octane, 5 gallons of VP 110 and 5 gallons of 91 octane
E85 tunes
Pump E85 can be used for stock turbo and mild big turbo tunes (up to 300 horsepower) if the fuel tests between 80% and 90% ethanol.
For all big turbo tunes above 300 horsepower, you must use either Ignite Orange or VP X85. Do not use VP C85 under any circumstances.
There are other, lesser-known ethanol-based fuels, which may or may not be good. VP's data sheets below show how much E85 fuels vary: compare the motor octane (MON) of X85 and C85. They aren't in the same league for knock resistance. VP C85 was designed to make power in a naturally aspirated vehicle, not a small, high-boost engine making 100+ horsepower per cylinder.
If you must use another fuel, insist on seeing its octane ratings, and make sure they're at least as good as VP X85. Don't take chances with your engine: use good fuel.
E85 spec sheets
Typical values from VP's data sheets (rev. 10/04/19).
| VP X85 (good) | VP C85 (bad) | |
|---|---|---|
| Color | Colorless | Yellow |
| Specific gravity | 0.7800 | 0.7940 |
| MON | 95.2 | 86.5 |
| RON | 108 | 106 |
| (R+M)/2 | 101.6 | 96.3 |
| Oxygen content | 30.03% | 31.97% |
| Oxidation stability (min.) | 1440+ | 1440+ |
| Leaded | No | No |
| RVP | 4.22 psi | 5.98 psi |
| Distillation IBP | 140.0°F | 119.8°F |
| 10% | 163.4°F | 153.9°F |
| 50% | 170.6°F | 167.0°F |
| 90% | 172.0°F | 171.0°F |
| FBP | 174.7°F | 182.3°F |
| H:C ratio | 2.85 | 2.85 |
| O:C ratio | 0.40 | 0.45 |
| Stoichiometric A/F ratio | 9.81 | 9.20 |
Need technical support?
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