String comparison
4G vs ALU Power
Luxilon 4G against Luxilon ALU Power: ratings, specs and which one fits your junior.
The short answer
Both are polyester strings. 4G leads on spin, durability and tension hold. ALU Power leads on power. They score the same for arm friendliness (2/5).
Ratings
Power
Spin
Control
Comfort
Durability
Tension hold
Ratings are on a 1–10 scale. The higher score is in bold when they differ.
Pick 4G if…
- You want more spin (8 vs 7 out of 10)
- You want more durability (9 vs 8 out of 10)
- You want more tension hold (10 vs 6 out of 10)
- You restring often and want it cheaper to keep up (cost score 4/5 vs 3/5)
- Best for: control-oriented advanced juniors
- Best for: players who hate restringing frequently
- Best for: players who value precision over power
Pick ALU Power if…
- You want more power (7 vs 6 out of 10)
- Best for: advanced juniors with full swings
- Best for: players who generate their own power
- Best for: tournament-level competitors
Specs side by side
| Spec | 4G | ALU Power |
|---|---|---|
| Type | Polyester | Polyester |
| Construction | Co-polyester monofilament with poly-ether-ether compound | Co-polyester monofilament |
| Gauges | 16, 16L | 16, 16L |
| Stiffness | High | Medium high |
| Set price | $21–22 | $21–22 |
| Reel price | $170–200 | $170–200 |
| Arm friendliness | 2/5 · Low | 2/5 · Low |
| Cost to maintain | 4/5 | 3/5 |
| Recommended from | Age 14 | Age 14 |
| Levels | Advanced, Elite | Advanced, Elite |
| Play styles | Baseliner, All court | Baseliner, Big hitter, All court |
| Junior tension | 48-52 lbs for juniors. Better tension maintenance means more consistent feel over time. | 48-52 lbs for juniors (vs 50-55 for adults). Start low and adjust. |
Lab test data
| Test | 4G | ALU Power |
|---|---|---|
| Stiffness (lower is softer) | 287 lbs/in | 232 lbs/in |
| Tension loss (lower holds tension better) | 21% | 28% |
| Spin potential (higher is more spin) | 4.5 | 4.2 |
Sources: Tennis Warehouse University (4G) · Tennis Warehouse University (ALU Power)
4G in short
Luxilon 4G was designed with one goal: better tension maintenance than ALU Power. Made with Luxilon's magical poly-ether-ether compound, 4G strings feature best-in-class durability, control and tension maintenance. Unlike many polys that go dead after 8-10 hours, 4G keeps its feel and control far longer. Its tension holding score of 100% isn't marketing hype - it's backed up by lab data. Control is where 4G shines, making it a workhorse that's reliable, consistent, and built for precision.
ALU Power in short
Luxilon ALU Power is the gold standard of co-poly monofilaments with an iconic pro tour pedigree. In addition to being one of the most popular choices on the ATP Tour, this string helped usher in the polyester revolution in tennis. The firm monofilament construction enables players to take huge cuts at the ball without losing control, generating massive stroke speed that produces a dangerous combination of pace and spin. Despite countless attempts to duplicate or improve it, this string remains the gold standard on the professional tour.
4G vs ALU Power: quick answers
Which has more spin, 4G or ALU Power?
Luxilon 4G, with a spin rating of 8/10 against 7/10.
Which is more arm-friendly for a junior?
They score the same, 2/5. 4G is recommended from age 14 and ALU Power from age 14.
Which lasts longer?
Luxilon 4G rates 9/10 for durability against 8/10.
Which is cheaper?
4G costs about $21–22 a set and ALU Power about $21–22, at typical retail.
The short answer and the "pick if" lists are generated from our ratings and junior data only. Data verified 2025-01 (4G) and 2025-01 (ALU Power).