Rockstar XDurance has more caffeine than C4 Performance Energy: 300mg vs 200mg in the same 16 oz can. That is a 100mg gap, and since the cans match, the per-serving number is the whole story.
Rockstar XDurance vs C4 Performance Energy: the numbers
| Rockstar XDurance | C4 Performance Energy | |
|---|---|---|
| Caffeine per serving | 300mg per 16 oz can | 200mg per 16 oz can |
| Caffeine per fl oz | 18.8mg | 12.5mg |
| Servings to reach 400mg (FDA context) | 1.3 | 2.0 |
Sources: Rockstar XDurance's figure is verified in our Rockstar XDurance caffeine guide against Rockstar product page / Caffeine Informer (source); C4 Performance Energy's figure is verified in our C4 Performance Energy guide against Caffeine Informer (source).
Which one should you pick?
Pick C4 Performance Energy when you want the lighter dose or a slower ramp, and Rockstar XDurance when you actually need the bigger hit and know your tolerance. If you are stacking either with other caffeinated drinks through the day, run the math against the 400mg reference rather than guessing.
For context, the FDA cites 400mg of caffeine a day as an amount generally not associated with negative effects in healthy adults. Tolerance and health vary, so treat these numbers as information, not advice.
Related reading
- Rockstar XDurance: the full caffeine guide
- C4 Performance Energy: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
FAQ
Does Rockstar XDurance or C4 Performance Energy have more caffeine? Rockstar XDurance: 300mg per 16 oz can versus 200mg per 16 oz can for C4 Performance Energy.
Which is stronger per ounce? Rockstar XDurance, at about 18.8mg per fluid ounce versus 12.5mg for C4 Performance Energy.
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