Rockstar XDurance has more caffeine than Dr Pepper on both counts: 300mg per 16 oz can against 41mg per 12 oz can, and about 19mg per fluid ounce against 3. The serving sizes differ, so the table below shows both ways of counting.
These are different categories of drink, which changes how the caffeine arrives. Energy drinks and sodas list an exact number because caffeine is a measured additive; brewed drinks vary with the beans and the brew, so their figures are compiled averages. The numbers here are the standard published values for each.
Rockstar XDurance vs Dr Pepper: the numbers
| Rockstar XDurance | Dr Pepper | |
|---|---|---|
| Caffeine per serving | 300mg per 16 oz can | 41mg per 12 oz can |
| Caffeine per fl oz | 18.8mg | 3.4mg |
| Servings to reach 400mg (FDA context) | 1.3 | 9.8 |
Sources: Rockstar XDurance's figure is verified in our Rockstar XDurance caffeine guide against Rockstar product page / Caffeine Informer (source); Dr Pepper's figure is verified in our Dr Pepper guide against KDP product facts / Caffeine Informer (source).
The concentration gap is the striking part: Rockstar XDurance packs roughly 5 times the caffeine per ounce. Sipping speed matters at that density; a 16 oz can finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick Dr Pepper 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
- Dr Pepper: 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 Dr Pepper have more caffeine? Rockstar XDurance: 300mg per 16 oz can versus 41mg per 12 oz can for Dr Pepper.
Which is stronger per ounce? Rockstar XDurance, at about 18.8mg per fluid ounce versus 3.4mg for Dr Pepper.
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