Buying guide
Compression Test Kits
Our pick
OTC Deluxe Compression Tester Kit
Our pick is the OTC Deluxe Compression Tester Kit for gasoline-engine checks. It includes a deep-well connector and spare seals.1
The alternatives
Other contenders
Choose the Innova 3612 for a 15-inch hose, quick-release connection and side release valve for repeated cylinder checks. Its instructions limit use to spark-ignited gasoline engines that do not exceed 250 psi; match the included fittings to the spark-plug opening.34
Choose the Mityvac MV5530 when you want one gauge with psi, bar, kPa and kg/cm² scales. It comes with 10, 12, 14 and 18 mm adapter options, a hard case and spare Schrader valves and O-ring seals.25
Choose the Tool Aid 34000 for gasoline-engine applications using its 14 or 18 mm connections. Its side release valve allows another check without removing the adapter; confirm the specified plug opening and application first.6
Choose the Tool Aid 34300 when you want 10, 12, 14 and 18 mm adapters together with a molded case and a repair kit containing O-rings, valve cores and an installation tool. Check the exact adapter and engine application before use.7
Buying advice
- Match your engine's spark-plug threads to an included adapter and check the kit's application list before buying.2
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5 products
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Models in this comparison
Every specification for these products
| Specification | OTC Deluxe Compression Tester Kit | Innova 3612 | Mityvac 5530 | Tool Aid 34000 | Tool Aid 34300 |
|---|---|---|---|---|---|
| Adapter sizes | with a 14-mm fitting on the end. OTC also includes 10-, 12- and 18-mm adapters2 | 12- 14- and 18-mm adapters2 | 14 mm short-thread x 18 mm long-thread adapter • 10 mm thread small engine adapter • 12 mm thread small engine adapter5 | 14mm and 18mm6 | 10mm, 12mm, 14mm and 18mm7 |
| Hose length | 25 in2 | 15 in3 | Not published | Not published | Not published |
| Deep-well adapter | Yes1 | Not published | Not published | Not published | Not published |
| Gauge units | 0 to 300 PSI and 0 to 2,100 kPa2 | 300 PSI2 | (psi, kg/cm², bar, kPa)5 | 0-300 PSI and 0-21 BAR6 | 0-300 PSI and 0-21 BAR7 |
| Dial size | Not published | Not published | 2.75 in5 | Not published | Not published |
| Case | Hard case1 | Not published | Hard case2 | Not published | Hard case7 |
| Spare seals included | Yes1 | Not published | Yes2 | Not published | Yes7 |
| Gauge protection | Yes1 | Not published | Yes2 | Not published | Not published |
| Small-engine use | Not published | Yes3 | Not published | Not published | Not published |
| Engine type | Gasoline1 | Gasoline (Tested configuration: Innova authored operating instructions for kits3612 and3614: spark-ignited gasoline engines which do not exceed250psi; gauge scale maximum is a separate quantity.)4 | Gasoline2 | Gasoline6 | Gasoline8 |
| Maximum gauge reading | 300 psi2 | 300 psi2 | 300 psi2 | 300 psi6 | 300 psi7 |
How they compare
Scroll the table to see every product and specification.
| Specification | Our pickOTC Deluxe Compression Tester Kit | Innova 3612 | Mityvac 5530 | Tool Aid 34000 | Tool Aid 34300 |
|---|---|---|---|---|---|
| Adapter sizes | with a 14-mm fitting on the end. OTC also includes 10-, 12- and 18-mm adapters2 | 12- 14- and 18-mm adapters2 | 14 mm short-thread x 18 mm long-thread adapter • 10 mm thread small engine adapter • 12 mm thread small engine adapter5 | 14mm and 18mm6 | 10mm, 12mm, 14mm and 18mm7 |
| Hose length | 25 in2 | 15 in3 | Not published | Not published | Not published |
| Deep-well adapter | Yes1 | Not published | Not published | Not published | Not published |
| Gauge units | 0 to 300 PSI and 0 to 2,100 kPa2 | 300 PSI2 | (psi, kg/cm², bar, kPa)5 | 0-300 PSI and 0-21 BAR6 | 0-300 PSI and 0-21 BAR7 |
| Dial size | Not published | Not published | 2.75 in5 | Not published | Not published |
| Case | Hard case1 | Not published | Hard case2 | Not published | Hard case7 |
| Spare seals included | Yes1 | Not published | Yes2 | Not published | Yes7 |
| Gauge protection | Yes1 | Not published | Yes2 | Not published | Not published |
| Small-engine use | Not published | Yes3 | Not published | Not published | Not published |
| Engine type | Gasoline1 | Gasoline (Tested configuration: Innova authored operating instructions for kits3612 and3614: spark-ignited gasoline engines which do not exceed250psi; gauge scale maximum is a separate quantity.)4 | Gasoline2 | Gasoline6 | Gasoline8 |
| Maximum gauge reading | 300 psi2 | 300 psi2 | 300 psi2 | 300 psi6 | 300 psi7 |