The Oakland Athletics had the highest run differential by a team in 1990, with a differential of 163 runs.

	TEAM	DIFF	SEASON	G	W%	W	L	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Athletics	163	1990	162	.636	103	59	5,433	733	1,379	209	22	164	693	651	46	992	141	54	6,238	2,124	395	60	48	38	122	.254	.336	.391	.727
2	Mets	162	1990	162	.562	91	71	5,504	775	1,410	278	21	172	734	536	32	851	110	33	6,182	2,246	471	54	56	65	89	.256	.323	.408	.731
3	Pirates	114	1990	162	.586	95	67	5,388	733	1,395	288	42	138	693	582	24	914	137	52	6,156	2,181	468	96	66	64	115	.259	.330	.405	.735
4	Blue Jays	106	1990	162	.531	86	76	5,589	767	1,479	263	50	167	729	526	28	970	111	52	6,223	2,343	480	18	62	35	125	.265	.328	.419	.747
5	Reds	96	1990	162	.562	91	71	5,525	693	1,466	284	40	125	644	466	42	913	166	66	6,163	2,205	449	88	42	73	99	.265	.325	.399	.724
6	Expos	64	1990	162	.525	85	77	5,453	662	1,363	227	43	114	607	576	26	1,024	235	99	6,189	2,018	384	87	47	67	96	.250	.322	.370	.692
7	White Sox	49	1990	162	.580	94	68	5,402	682	1,393	251	44	106	637	478	36	903	140	90	6,038	2,050	401	75	47	50	112	.258	.320	.379	.699
8	Dodgers	43	1990	162	.531	86	76	5,491	728	1,436	222	27	129	669	538	31	952	141	65	6,179	2,099	378	71	48	78	110	.262	.328	.382	.711
9	Red Sox	35	1990	162	.543	88	74	5,516	699	1,502	298	31	106	660	598	28	795	53	52	6,234	2,180	435	48	44	59	174	.272	.344	.395	.739
10	Giants	9	1990	162	.525	85	77	5,573	719	1,459	221	35	152	681	488	33	973	109	56	6,215	2,206	408	76	45	61	83	.262	.323	.396	.718
11	Padres	0	1990	162	.463	75	87	5,554	673	1,429	243	35	123	628	509	28	902	138	59	6,218	2,111	401	79	48	75	117	.257	.320	.380	.700
12	Royals	-2	1990	161	.466	75	86	5,488	707	1,465	316	44	100	660	498	27	879	107	62	6,098	2,169	460	31	54	32	132	.267	.328	.395	.723
13	Tigers	-4	1990	162	.488	79	83	5,479	750	1,418	241	32	172	714	634	34	952	82	57	6,224	2,239	445	36	41	44	139	.259	.337	.409	.746
14	Indians	-5	1990	162	.475	77	85	5,485	732	1,465	266	41	110	675	458	29	836	107	52	6,087	2,143	417	54	61	33	122	.267	.324	.391	.714
15	Angels	-16	1990	162	.494	80	82	5,570	690	1,448	237	27	147	646	566	28	1,000	69	43	6,267	2,180	411	58	45	41	142	.260	.329	.391	.720
16	Rangers	-20	1990	162	.512	83	79	5,469	676	1,416	257	27	110	641	575	34	1,054	115	48	6,176	2,057	394	54	44	45	142	.259	.331	.376	.707
17	Brewers	-28	1990	162	.457	74	88	5,503	732	1,408	247	36	128	680	519	33	821	164	72	6,185	2,111	411	59	71	46	101	.256	.320	.384	.704
18	Orioles	-29	1990	161	.472	76	85	5,410	669	1,328	234	22	132	623	660	40	962	94	52	6,223	2,002	388	72	41	50	131	.245	.330	.370	.700
19	Mariners	-40	1990	162	.475	77	85	5,474	640	1,419	251	26	107	610	596	40	749	105	51	6,205	2,043	384	41	54	41	140	.259	.333	.373	.707
20	Twins	-63	1990	162	.457	74	88	5,499	666	1,458	281	39	100	625	445	53	749	96	53	6,086	2,117	420	40	49	32	148	.265	.324	.385	.708
21	Phillies	-83	1990	162	.475	77	85	5,535	646	1,410	237	27	103	619	582	30	915	108	35	6,245	2,010	367	59	39	92	115	.255	.327	.363	.690
22	Astros	-83	1990	162	.463	75	87	5,379	573	1,301	209	32	94	536	548	28	997	179	83	6,075	1,856	335	79	41	64	107	.242	.313	.345	.658
23	Cubs	-84	1990	162	.475	77	85	5,600	690	1,474	240	36	136	649	406	30	869	151	50	6,148	2,194	412	61	51	68	100	.263	.314	.392	.706
24	Cardinals	-99	1990	162	.432	70	92	5,462	599	1,398	255	41	73	554	517	21	844	221	74	6,127	1,954	369	77	50	54	101	.256	.320	.358	.678
25	Braves	-139	1990	162	.401	65	97	5,504	682	1,376	263	26	162	636	473	27	1,010	92	55	6,084	2,177	451	49	31	36	101	.250	.311	.396	.706