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40–45 kW Diesel Generator Fuel Consumption

Manufacturer-documented fuel consumption for 47 40–45 kW Diesel generator sets — median 3.09 gal/h at full load, 1.59 gal/h at half load.

Compare 40–45 kW Diesel generator specs side-by-side →

Consumption by model

Model	kW	gal/h @ 50%	gal/h @ 100%	Tank (L)	Runtime @ 50% (h)
Aurora Generators AGi40H	40	1.39	2.08	45	8.6
Caps CP50-TP1	40	1.51	2.83	160	28.1
Caterpillar D40	40	2.01	3.33	4	0.6
Cummins/Onan 36 DGBC	40	—	3.38	197	—
Cummins/Onan 40.0 DEF-15R50	40	—	3.51	—	—
Cummins/Onan 40.0 DEF-3R50	40	—	3.51	—	—
Cummins/Onan 40.0DDB-515R	40	—	1.03	—	—
Cummins/Onan C40 D6	40	—	2.20	200	—
Cummins/Onan DGBC	40	—	2.91	24	—
Cummins/Onan DGCA	40	—	2.91	24	—
Emsa E BD XX 0050	40	0.69	1.24	101	38.8
FG Wilson P40	40	1.35	2.77	219	42.9
FG Wilson P50-1	40	0.74	2.64	219	78.2
FG Wilson P50-3_50Hz	40	1.48	3.09	143	25.5
FG Wilson P50E1	40	—	3.14	176	—
Generac SD040	40	1.93	3.51	211	28.9
Kohler 40 REOZK4	40	1.61	3.09	293	48.0
Kohler 40EFOZ	40	1.64	3.04	—	—
Kohler 40EKOZD	40	1.66	3.09	—	—
Kohler 40EORZD	40	1.53	2.83	—	—
Kohler 40EOZ	40	1.45	2.67	—	—
Kohler 45 REOZT4	40	1.32	3.09	293	58.6
Kohler 45EFOZDJ	40	2.55	4.66	—	—
MQ Power DCA45USIXF	40	1.51	0.70	751	131.8
MTU 4R0113 DS40	40	1.37	2.62	—	—
MTU 4R0113 DS40 SCAQMD	40	1.37	2.62	—	—
MTU MTU 4R0113 DS40	40	1.37	2.62	—	—
Northern Lights L439	40	2.64	0.40	200	20.0
Northern Lights M40C3F	40	1.60	3.26	—	—
Olympian GEP50-7	40	1.59	3.09	219	36.5
SDMO J40U	40	—	3.46	—	—
SDMO JM40UC	40	1.83	3.46	—	—
Simson-Maxwell SDW55 T6-T2	40	1.77	3.22	322	48.1
Westquip WQ40T4H	40	1.45	2.90	—	—
Cummins/Onan 4BTAA3.3-G18	42	1.59	3.17	—	—
Kohler 40REOZK	42	2.01	3.49	—	—
Kohler 40REOZT	42	1.61	3.22	—	—
Mitsubishi MDG40	42	1.59	3.17	—	—
Caterpillar D60	44	—	4.94	—	—
Emsa E BD XX 0055	44	0.69	1.24	101	38.8
FG Wilson P55-1	44	1.27	2.56	219	45.6
FG Wilson P55-2	44	1.27	3.09	219	45.6
FG Wilson P55-3	44	2.01	3.62	145	19.1
Generac MMG45IF4	44	—	2.06	379	—
MTU 4R0113 DS55	44	1.95	3.54	—	—
Olympian GEP55-3	44	2.01	3.59	219	28.8
Perkins 1104C-44G1	44	10.30	12.42	—	—

Figures from each model’s own manufacturer documentation (spec sheets and manuals); runtime = documented tank capacity ÷ consumption at 50% load. Verify against the datasheet for your exact configuration.

Common questions

How much fuel does a 40–45 kW Diesel generator use?

Across 47 models with manufacturer data, full-load consumption runs 0.40–12.42 gal/h (median 3.09); at 50% load the median is 1.59 gal/h.

How long will a 40–45 kW Diesel generator run on a full tank?

At 50% load, documented tank sizes give 0.6–131.8 hours (median 38.8 h) across 19 models.