VP 110 and C12 are both leaded, non-oxygenated racing gasolines. VP lists both at 108 MON, but their AKI ratings differ: 110.5 for VP 110 and 112 for C12. Those numbers do not make the fuels interchangeable. Start with the exact fuel your engine builder specifies, then compare the product sheet, event requirements and order details.
VP 110 and C12 specifications, side by side
The figures below are typical manufacturer values checked September 11, 2026, on the VP 110 product page and VP C12 product page. Confirm the current specification for the product you are ordering.
| Specification | VP 110 | VP C12 |
|---|---|---|
| Motor Octane Number (MON) | 108 | 108 |
| Research Octane Number (RON) | 113 | 116 |
| Anti-Knock Index, (R+M)/2 | 110.5 | 112 |
| Lead status | Leaded | Leaded |
| Oxygen content | 0% | 0% |
Read across the same row when comparing fuels. An advertised product name, a MON value and an AKI value are different things. For example, C12's 112 AKI should be compared with VP 110's 110.5 AKI, not its 108 MON.
AKI is the average of RON and MON. Octane measures resistance to knock; it is not a measure of energy content or a promise of extra horsepower. Sunoco's race-fuel explanation explains why fuel selection and the engine's calibration need to work together.
Check compatibility before choosing an octane number
The first question in a leaded vs unleaded race fuel comparison is whether the application can use leaded fuel at all. Sunoco identifies catalytic converters and oxygen sensors as reasons to use unleaded fuel. A requirement for unleaded fuel takes both of these blends out of consideration; choosing the higher octane number does not resolve that requirement.
Next, ask what your current tune was developed around. Two fuels sharing one specification are not automatically approved substitutes. Give the builder both complete specification sheets and ask for an exact product recommendation before changing the fuel in the tank.
VP describes VP 110 for naturally aspirated engines with compression ratios up to 12:1 and C12 for applications up to 15:1 on the linked product pages. These are manufacturer application descriptions, not a stand-alone selection chart for your engine. Do not treat compression ratio alone as approval for a particular fuel.
Five questions to send your engine builder
A useful fuel recommendation should be specific enough to order against. Send the following questions together with the engine details and current fuel. Keep the reply with your build or service records so a later purchase does not depend on someone remembering a conversation.
- Which exact blend does this engine require? Include the engine build, modifications, intended use and current fuel specification.
- Does the recommendation match the current tune? Ask whether a change needs calibration work or checks before use; do not substitute your own mixing formula.
- Can the complete fuel system use leaded fuel? Include the sensors and emissions equipment actually fitted.
- What does the event permit? Provide the organizer's current fuel rules or approved-fuel list rather than relying on last season's requirements.
- What should happen if that blend is unavailable? Obtain an approved alternative, or plan to wait for the specified product instead of choosing by price or octane alone.
If the answer is simply that the engine should remain on its specified pump fuel, that is a useful outcome. Our race fuel vs pump gas guide provides a decision worksheet for that earlier step.
Common VP 110 and C12 questions
Is VP 110 leaded? Yes. VP's current specification lists VP 110 as leaded. Do not confuse it with a different unleaded VP product or assume that a familiar octane number identifies a fuel's composition.
Is C12 better than VP 110? There is no universal winner for every engine. The table establishes differences in published specifications; it does not establish an engine-specific performance result. An exact builder recommendation is more useful than a blanket ranking.
Can I switch because both have 108 MON? That shared value alone does not establish compatibility. Ask the builder to review the full fuel specification, tune and application.
How long will VP 110 last? Ask for storage guidance for the exact blend and container history. Our VP Racing fuel shelf-life guide explains what to record before deciding how much to buy.
Turn the fuel decision into a clear quote request
Once the blend is confirmed, compare offers using the same product and actual net gallons. Our VP fuel price guide includes a worksheet that separates the fuel charge from other quoted costs. A cheaper order for a different blend is not a like-for-like comparison.
Navillus Petroleum's office is in Mojave, California. Review our VP Racing fuel offering, then send the exact blend, quantity, receiving location and needed date. Ask us to confirm the available package and fulfillment arrangements before making travel or event plans. C12 availability needs confirmation; this comparison is not a stock listing.
Request VP Racing fuel availability and a quote. Include the builder-approved product name so the conversation begins with the fuel you actually need.