HomeCummins/OnanCummins/Onan qsB4.5

Cummins/Onan qsB4.5 Generator Set

The Cummins/Onan qsB4.5 is a generator set powered by a Cummins/Onan QSB4.5 engine. It holds about 11.6 L (3.1 gal) of oil and 13 L (3.4 gal) of coolant.

4.5 L
Displacement
11.6 L
Oil capacity
3
Document types

How to read your Cummins/Onan serial & model number →

Service parts for the qsB4.5

Grouped by system, with how many of each the parts manual calls for.

Oil system

1 required

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

EmissionsEPA Tier 4 Final/EU Stage IV
Oil capacity11.6 L

Engine

Cummins/Onan QSB4.5
Oil capacity11.6 L
Coolant capacity13.0 L
Displacement4.5 L
AspirationTurbocharged and Charge-Air Cooled
Rated speed1470 rpm

Maintenance & consumables

for the Cummins/Onan QSB4.5
ItemSpecCapacityPart #Interval
Fuel filterRecommended fuel filter - primary Cummins Filtration FF5612 (Cummins 4989106); secondary element AF26125
Oil filterRecommended lube oil filter - Cummins Filtration LF3970LF3970 Amazon $36.06 eBay $177.58 FridayParts $62.99
BatteryBattery cable size - minimum of 2/0 AWG and maximum cable length not to exceed 6 ft. (1.5 m)
BeltExhaust protection - Metal guards on manifolds and turbocharger; Exhaust flex connection - Steel, flanged; Stainless steel flex, NPT
CoolantCooling system - Tube and shell type, 60 PSI with NPTF connections; recommended minimum water supply pipe size to heat exchanger .75 in. (19.05 mm); recommended minimum water discharge pipe size from heat exchanger 1.00 in. (25.40 mm)
OilOil capacity of pan (high - low) 11.6-9.5 qt. (11-9 L)
Spark plugEngine only - cold cranking amperes: 1300 CCA*; Engine only - reserve capacity: 430 minutes*

Service intervals

5
ItemActionHoursMonthsNotes
Lubricating oilTest250 hr6 moFirst service — For high horsepower engines with Eliminator™ oil filter option: take oil samples every 250 hours and analyze per Cummins Engine Oil Recommendations Bulletin 3810340; repeat for at least three oil change intervals.
filtersChange1000 hrwith CENTINEL, depending on load factors
ELIMINATOR self cleaning filter coreOther1500 hrRequires servicing only every 1,500 hours. Saves up to 90% of lube system maintenance costs and increases productivity.
fuel filterChange1500 hrFleetguard NanoNet media
engine oilChange4500 hrwith CENTINEL, railway applications

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Engine oilCummins Engine Oil Recommendations Bulletin 3810340Used to analyze oil samples for high horsepower engines with Eliminator™ oil filter option.
FuelB100 biodieselASTM D6751Must conform prior to blending; revised to include a cold soak test; stability requirement still in effect.
FuelB20 biodiesel blendASTM D7467Applies to biodiesel blends B6–B20; includes oxidation stability requirement; replaces Cummins' previous EMA B20 specification requirement. Must be purchased from a BQ9000 Certified Marketer; B100 must be sourced from a BQ9000 Accredited Producer.
FuelB5 biodieselAll Cummins automotive and industrial engines are compatible with B5 biodiesel.
Fuelbiodiesel (Europe)EN 14214Published by CEN, European Committee for Standardization. Equivalent biodiesel specifications required internationally.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

2
Oil sampling for high horsepower engines with Eliminator™ oil filter option maintenance
  1. Take oil samples every 250 hours of operation.
  2. Analyze samples according to Cummins Engine Oil Recommendations Bulletin 3810340.
  3. Repeat for at least three oil change intervals to ensure consistent oil behavior.
Switching from petrodiesel to B20 on used engines maintenance

⚠ B20 has a solvent nature and may clean the vehicle fuel tank and lines.

  1. Install new fuel filters when switching to B20.
  2. Replace fuel filters at half the standard interval for the next two fuel filter changes.
  3. After the initial period, revert to intervals specified in the O & M manual.
  4. For EPA 2007 on-highway midrange engines, sample oil for the first 6 months to monitor fuel dilution.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What engine is in the Cummins/Onan qsB4.5?

The Cummins/Onan qsB4.5 is powered by the Cummins/Onan QSB4.5 engine.

What is the oil capacity of the Cummins/Onan qsB4.5?

The Cummins/Onan QSB4.5 engine in the Cummins/Onan qsB4.5 has an oil capacity of 11.6 liters.

Which oil filter part number does the Cummins/Onan qsB4.5 take?

The Cummins/Onan qsB4.5 uses oil filter part number LF3970.

Parts

6model family
Part #DescriptionQtySystem
QSB4.5Service part / kit FridayParts $7.50
QSB6.7MotorService part / kit FridayParts $7.50
QSF2.8Electronic, 49 - 74 hp (37 - 55 kW)Service part / kit FridayParts $15.45
QSF3.8Service part / kit FridayParts $21.75
QSG12Service part / kit Amazon eBay FridayParts $12.35
QSX15QSZ13*Service part / kit Amazon eBay FridayParts $8.65

Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Available documents

Engine spec — 0032276 (Cummins/Onan)Engine spec — 4087063 (Cummins/Onan)Engine spec — cummins-QSB-5.9-industrial-tier-3-specs (Cummins/Onan)Engine spec — cummins-QSB-off-highway-specs (Cummins/Onan)Reference — 0032425 (Cummins/Onan)Reference — 0058562 (Cummins/Onan)Reference — 0059591 (Cummins/Onan)Reference — QST30 nuevo (Cummins/Onan)Service manual — B20BiodieselFAQJan2009 (Cummins/Onan)
Full service, cheapest listings

Priced items from this model's own parts manual.

Oil filter LF3970$36.06
1 priced item$36.06