Red Line SI-1 Complete Fuel System Cleaner, 15 oz
As an Amazon Associate, I earn from qualifying purchases.
✓ Pros
- +Concentrated blend of high-temp and low-temp detergents targets injector, carburetor, valve and combustion chamber deposits
- +Simple dosing: one 15 oz bottle per tank, and it also helps stabilize fuel against gum and varnish
- +Rated 4.8 stars from nearly 11,000 reviews, with 7K+ bought in the past month
✗ Cons
- −At about $18 a bottle and one bottle per tank, it costs more per treatment than most store-brand cleaners, so it's best used every few thousand miles, not every fill-up
- −It's a cleaner, not a repair: a failed injector or fuel pump still needs a mechanic (the listing had no review summary, so these points come from the product design)
How we judged this one: we have not tested it hands-on yet. This summary comes from the listing, the specs, and patterns in buyer reviews.
Compare Similar Products
See how this compares with the closest matching alternatives in our catalog.
| Product | Rating | Reviews | Badge | Shop |
|---|---|---|---|---|
| 4.8★ | 10K+ | Best Seller | ||
| 4.8★ | 36K+ | Best Seller | ||
| 4.6★ | 46K+ | Best Seller | ||
| 4.6★ | 11K+ | Best Seller | ||
| 4.5★ | 94.5K+ | Best Seller |
Guides Featuring Auto & Garage
Side-by-side comparisons that include this product or its closest alternatives.
5 Best Gifts for Car Lovers on Amazon (2026)
Five car gifts with 4.4+ stars on Amazon: the NOCO Boost GB40 jump starter, a Chemical Guys 16-piece wash kit, the Cerakote headlight restoration kit, the iOttie Easy One Touch phone mount and the AstroAI windshield cleaner tool.
Auto5 Winter Car Emergency Kit Essentials on Amazon (2026)
Five winter car emergency kit essentials with 4.6+ stars on Amazon, led by the FosPower NOAA weather radio, with honest downsides for each, plus what else to pack and how to check the kit before winter.
Auto5 Best Portable Car Jump Starters on Amazon for Dead Batteries (2026)
Five high-review portable jump starters for everyday cars, larger gas engines, and diesel vehicles—plus the safety and sizing details that matter before you buy.