Can I use X size tire?
	Here is the answer, for OEM using 15x4.5x5 rims.
	there are two aspects, diameter and width.  Width affects if there will be rubbing on the inside or outside of the wheel well
	note:  this does NOT factor in "rolling radius", which is hard to find.
									Width difference, based on Rim Used
									OEM RIM		FORD RIM
	Rim Diameter	Section Width	Aspect Ratio	Tire Diameter (inches)	Tire Diameter over Stock	Tire Width over Stock	Tire Diameter over Stock	MPH Error at 60 MPH	Extra inch Outside	Extra inch Inside	Extra inch Outside	Extra inch Inside
OEM (inches)	15	6.7	0.9	27.06	0.00	0	0.00%	44719	2.48	4.23	2.85	3.85
Modern (metric)	15	170	0.9	27.05	-0.01	-0.00709	-0.05%	-0.0283	0.00	0.00	-0.38	0.37
Aspect Ratio 80
	15	190	0.8	26.97	-0.09	0.780315	-0.34%	-0.2036	0.39	0.39	0.02	0.77
	15	195	0.8	27.28	0.22	0.977165	0.83%	0.4914	0.49	0.49	0.11	0.86
	15	200	0.8	27.60	0.54	1.174016	1.99%	1.1706	0.59	0.59	0.21	0.96
	15	205	0.8	27.91	0.85	1.370866	3.15%	1.8344	0.69	0.69	0.31	1.06
	15	210	0.8	28.23	1.17	1.567717	4.32%	2.4833	0.78	0.78	0.41	1.16
Aspect Ratio 75
	15	200	0.75	26.81	-0.25	1.174016	-0.92%	-0.5572	0.59	0.59	0.21	0.96
	15	205	0.75	27.11	0.05	1.370866	0.17%	0.1025	0.69	0.69	0.31	1.06
	15	210	0.75	27.40	0.34	1.567717	1.26%	0.7479	0.78	0.78	0.41	1.16
	15	215	0.75	27.70	0.64	1.764567	2.35%	1.3796	0.88	0.88	0.51	1.26
	15	220	0.75	27.99	0.93	1.961417	3.44%	1.9980	0.98	0.98	0.61	1.36
Aspect Ratio 70
	15	215	0.7	26.85	-0.21	1.764567	-0.77%	-0.4684	0.88	0.88	0.51	1.26
	15	220	0.7	27.13	0.07	1.961417	0.24%	0.1460	0.98	0.98	0.61	1.36
	15	225	0.7	27.40	0.34	2.158268	1.26%	0.7479	1.08	1.08	0.70	1.45
	15	230	0.7	27.68	0.62	2.355118	2.28%	1.3379	1.18	1.18	0.80	1.55
	15	235	0.7	27.95	0.89	2.551969	3.30%	1.9163	1.28	1.28	0.90	1.65
16 inch Rim?
Aspect Ratio 70
	16	200	0.7	27.02	-0.04	1.174016	-0.13%	-0.0808
	16	205	0.7	27.30	0.24	1.370866	0.88%	0.5258
	16	210	0.7	27.57	0.51	1.567717	1.90%	1.1202
	16	215	0.7	27.85	0.79	1.764567	2.92%	1.7028
	16	220	0.7	28.13	1.07	1.961417	3.94%	2.2740
Aspect Ratio 65	16	215	0.65	27.00	-0.06	1.764567	-0.21%	-0.1246
	16	220	0.65	27.26	0.20	1.961417	0.74%	0.4399
	16	225	0.65	27.52	0.46	2.158268	1.68%	0.9938
	16	230	0.65	27.77	0.71	2.355118	2.63%	1.5375
	16	235	0.65	28.03	0.97	2.551969	3.58%	2.0713