BG BG109 Compression Engine Performance Restore (11 oz) — restores compression, dissolves piston-ring deposits

BG109 Compression Engine Performance Restore (BG EPR) is an 11 oz. treatment designed to soften and remove stubborn oil and piston-ring deposits to help regain lost compression and improve engine smoothness.

BG EPR (originally BG 109) is a concentrated engine treatment used during oil service that targets hardened deposits and micro-contaminants inside the crankcase and ring area. Introduced in 2005 and continually refined, this formula is intended to dissolve the varnish and sludge that restrict ring movement and block micro passageways in modern engines, helping restore more uniform compression across cylinders when combined with normal maintenance.

How does BG EPR help engines that sound rough or low on power?

The product works by softening baked-on deposits on piston rings and cylinder walls so those rings can reseat and restore compression. It also helps clear micro passageways that affect hydraulic actuators and turbochargers, improving responsiveness and reducing noise.

• Dissolves hardened sludge and varnish on rings and pistons
• Supports improved ring sealing for better compression
• Helps reduce valve-train and lifter noise by clearing passages

When and how should BG109 be applied during service?

BG EPR is added during an oil change as part of the service procedure; typical results are seen after one or two oil changes when deposits have been loosened and expelled. Technicians clean accessible covers, add the treatment to the fresh oil, then complete regular filter and oil replacement steps.

• Use during an oil change; compatible with routine service intervals
• Best results often observed after two consecutive oil changes with treatment
• Follow normal disposal and safety precautions for used oil and filters

What measurable improvements can a technician expect after using BG EPR?

Independent before-and-after compression tests have shown increased compression values and improved balance between cylinders on many vehicles. Technicians report smoother idle, reduced knock or diesel-like noise, and restored drivability in engines previously considered for replacement.

• Documented rise in compression readings on affected engines
• Improved balance between low and high cylinders
• Noticeable reduction in engine noise and roughness

Are there engine types or conditions where BG EPR is most effective?

BG EPR is formulated for modern gasoline and light-duty engines that have experienced deposit buildup from extended oil intervals or contaminated oil. It is particularly useful when rings are sticky or when hydraulic components are impaired by varnish, though severely mechanically damaged engines may require additional repair.

• Effective on engines with varnish, sludge, or sticky rings
• Helpful for engines affected by prolonged oil-change intervals
• Not a replacement for mechanical repairs on physically damaged components

Who is this for: BG109 BG EPR is aimed at professional technicians, independent shops, and knowledgeable DIYers performing oil service who need a concentrated chemical solution to tackle stubborn internal deposits. It is a useful, cost-effective option when compression loss and deposit-related drivability issues are suspected, offering a potential alternative to more invasive and expensive engine repairs.

• Contains the latest production date stamped on the bottom of the can
• Cleans critical micro passageways affecting valve actuators and turbochargers
• Helps prevent excessive oil loss by addressing ring seal issues
• Softens and dissolves hard-to-remove piston-ring deposits

Ingredients

BG109 Compression Engine Performance Restore BG EPR