10 Best line additives of 2026

Save up to 40% off

1

Red Line
Red Line 60103 SI-1 Complete Fuel System Cleaner, Cleans and Prevents Corrosion in Fuel Systems, Cleans Injectors, Carburetors, Valve and Combustion Chamber Deposits - 15 Ounce (2 Pack)
Main highlights

Comprehensive Cleaning and Protection
Red Line SI-1 cleans injectors, carburetors, valves, and prevents corrosion.

Ideal for Performance Boost
Best used in vehicles needing enhanced performance and smoother engine operation.

Customer-Praised Performance Improvement
Notable increase in vehicle performance and fuel efficiency.
9.6

Exceptional

Our Rating

9.9
Simple to use

9.3
Precision

9.1
worth the money
How do we rank?

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Based on millions of stores and reviews

Shoppers influence our rankings
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2

Red Line

Red Line 81403 Engine Oil Break-In Additive - 16 Ounce

19% Off
9.5

Excellent

Our Rating
3

Heet
HEET Water Remover & Premium Gas Line Antifreeze, Removes Water from Fuel System, Prevents Gas-line Freezing, Winter Fuel Additive for Fast Cold Weather Starts, 12 fl. oz.

40% Off
Main highlights

Efficient Filtering and Water Separation
Keeps fuel line clean and free of water, preventing rust and corrosion for smoother engine operation.

Perfect for Winter Starts
Ideal for ensuring fast cold weather starts by preventing gas-line freezing in all 4-cycle engines.

Reliable Moisture Absorption
Customers praise its ability to absorb moisture effectively, protecting the fuel system from damage.
Key specs
- Brand:Heet
- Model:Antifreeze/Water Remover
- Battery Life:N/A
- Screen Size:N/A
- RAM Size:N/A
9.4

Excellent

Our Rating
4

Heet
HEET Water Remover & Premium Gas Line Antifreeze, Removes Water from Fuel System, Prevents Gas-line Freezing, Winter Fuel Additive for Fast Cold Weather Starts, 12 fl. oz.

40% Off
Main highlights

Efficient Filtering and Water Separation
Keeps fuel line clean and free of water, preventing rust and corrosion for smoother engine operation.

Perfect for Winter Starts
Ideal for ensuring fast cold weather starts by preventing gas-line freezing in all 4-cycle engines.

Reliable Moisture Absorption
Customers praise its ability to absorb moisture effectively, protecting the fuel system from damage.
Key specs
- Brand:Heet
- Model:Antifreeze/Water Remover
- Battery Life:N/A
- Screen Size:N/A
- RAM Size:N/A
9.3

Excellent

Our Rating
5

Red Line

Red Line 81403 Engine Oil Break-In Additive - 16 Ounce

19% Off
9.2

Excellent

Our Rating
See Today’s Deals & Prices
6

Red Line
Red Line 60103 SI-1 Complete Fuel System Cleaner, Cleans and Prevents Corrosion in Fuel Systems, Cleans Injectors, Carburetors, Valve and Combustion Chamber Deposits - 15 Ounce
Main highlights

Comprehensive Cleaning Power
Red Line SI-1 effectively cleans injectors, carburetors, and valves.

Ideal for Older Vehicles
Best used in vehicles with suspected fuel system fouling.

Notable Mileage Improvement
Customers report significant gas mileage increases after treatment.
Key specs
- Application Method:One bottle per tank
- Performance Improvement:Enhances gasoline stability
- Volume:15 Ounce
- Compatibility:Fuel systems
- Cleaner Function:Cleans injectors and carburetors
8.9

Very Good

Our Rating

9.7
Simple to use

9.5
quality of ingredients

9.3
worth the money
7

Red Line
Red Line 60103 SI-1 Complete Fuel System Cleaner, Cleans and Prevents Corrosion in Fuel Systems, Cleans Injectors, Carburetors, Valve and Combustion Chamber Deposits - 15 Ounce
Main highlights

Comprehensive Cleaning Power
Red Line SI-1 effectively cleans injectors, carburetors, and valves.

Ideal for Older Vehicles
Best used in vehicles with suspected fuel system fouling.

Notable Mileage Improvement
Customers report significant gas mileage increases after treatment.
Key specs
- Application Method:One bottle per tank
- Performance Improvement:Enhances gasoline stability
- Volume:15 Ounce
- Compatibility:Fuel systems
- Cleaner Function:Cleans injectors and carburetors
8.6

Very Good

Our Rating

9.7
Simple to use

9.5
quality of ingredients

9.3
worth the money
8

Red Line

Red Line 80301 Limited Slip Friction Modifier - 4 Ounce
8.5

Good

Our Rating
9

Red Line

Red Line 80301 Limited Slip Friction Modifier - 4 Ounce
8.4

Good

Our Rating
10

Red Line

Red Line 80204 WaterWetter Super Coolant - 12 Ounce

13% Off
8.2

Good

Our Rating

10 Best line additives of 2026

1

Red Line 60103 SI-1 Complete Fuel System Cleaner, Cleans and Prevents Corrosion in Fuel Systems, Cleans Injectors, Carburetors, Valve and Combustion Chamber Deposits - 15 Ounce (2 Pack)

9.9

9.3

9.1

How do we rank?

How do we rank?

Analyzing top stores

2

Red Line 81403 Engine Oil Break-In Additive - 16 Ounce

3

HEET Water Remover & Premium Gas Line Antifreeze, Removes Water from Fuel System, Prevents Gas-line Freezing, Winter Fuel Additive for Fast Cold Weather Starts, 12 fl. oz.

4

HEET Water Remover & Premium Gas Line Antifreeze, Removes Water from Fuel System, Prevents Gas-line Freezing, Winter Fuel Additive for Fast Cold Weather Starts, 12 fl. oz.

5

Red Line 81403 Engine Oil Break-In Additive - 16 Ounce

6

Red Line 60103 SI-1 Complete Fuel System Cleaner, Cleans and Prevents Corrosion in Fuel Systems, Cleans Injectors, Carburetors, Valve and Combustion Chamber Deposits - 15 Ounce

9.7

9.5

9.3

7

Red Line 60103 SI-1 Complete Fuel System Cleaner, Cleans and Prevents Corrosion in Fuel Systems, Cleans Injectors, Carburetors, Valve and Combustion Chamber Deposits - 15 Ounce

9.7

9.5

9.3

8

Red Line 80301 Limited Slip Friction Modifier - 4 Ounce

9

Red Line 80301 Limited Slip Friction Modifier - 4 Ounce

10

Red Line 80204 WaterWetter Super Coolant - 12 Ounce

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