The Cincinnati Reds had the highest run differential by a team in 1940, with a differential of 179 runs.

	TEAM	DIFF	SEASON	G	W%	W	L	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	GIDP	AVG	OBP	SLG	OPS
1	Reds	179	1940	155	.654	100	53	5,372	707	1,427	264	38	89	649	453	36	503	72		5,986	2,034	391	125	108	.266	.327	.379	.706
2	Tigers	172	1940	155	.584	90	64	5,418	888	1,549	312	65	134	829	664	24	554	66	39	6,183	2,393	511	77	115	.286	.366	.442	.808
3	Yankees	146	1940	155	.571	88	66	5,286	817	1,371	243	66	155	759	647	36	605	59	36	6,045	2,211	464	76	124	.259	.344	.418	.762
4	Dodgers	76	1940	156	.575	88	65	5,470	697	1,421	256	70	93	653	522	20	570	56		6,089	2,096	419	77	112	.260	.327	.383	.710
5	Indians	73	1940	155	.578	89	65	5,361	710	1,422	287	61	101	661	519	16	598	53	36	5,957	2,134	449	61	111	.265	.332	.398	.730
6	White Sox	63	1940	155	.532	82	72	5,386	735	1,499	238	63	73	671	497	10	569	52	60	6,003	2,082	374	110	123	.278	.340	.387	.727
7	Cardinals	48	1940	156	.549	84	69	5,499	747	1,514	266	61	119	709	479	21	610	97		6,087	2,259	446	88	103	.275	.336	.411	.747
8	Red Sox	47	1940	154	.532	82	72	5,481	872	1,566	301	80	145	808	590	12	597	55	49	6,174	2,462	526	91	129	.286	.356	.449	.806
9	Cubs	45	1940	154	.487	75	79	5,389	681	1,441	272	48	86	627	482	29	566	63		5,970	2,067	406	70	108	.267	.331	.384	.714
10	Pirates	24	1940	156	.506	78	76	5,466	809	1,511	276	68	76	740	553	33	494	69		6,115	2,151	420	63	116	.276	.346	.394	.740
11	Giants	3	1940	152	.474	72	80	5,324	663	1,423	201	46	91	614	453	37	478	45		5,900	1,989	338	86	130	.267	.329	.374	.703
12	Bees	-122	1940	152	.428	65	87	5,329	623	1,366	219	50	59	558	402	17	581	48		5,810	1,862	328	62	101	.256	.311	.349	.660
13	Browns	-125	1940	156	.435	67	87	5,416	757	1,423	278	58	118	715	556	16	638	51	40	6,051	2,171	454	63	105	.263	.333	.401	.734
14	Senators	-146	1940	154	.416	64	90	5,365	665	1,453	266	67	52	602	465	18	504	94	40	5,909	2,009	385	61	100	.271	.331	.374	.706
15	Athletics	-229	1940	154	.351	54	100	5,304	703	1,391	242	53	105	648	556	19	655	48	33	5,948	2,054	400	69	127	.262	.334	.387	.722
16	Phillies	-256	1940	153	.327	50	103	5,137	494	1,225	180	35	75	459	435	14	527	25		5,673	1,700	290	87	115	.238	.300	.331	.631