With the recent government mandated fuel economy standards, there has been a lot of confusion on what is cost-effective, and how much money will be saved with various standards will across the fleet of vehicles. Here is some tables that will help you understand what various improvements on fuel economy really mean.

MPG Improvements.

MPG	10%	20%	30%	40%	50%
10	11	12	13	14	15
15	16.5	18	19.5	21	22.5
20	22	24	26	28	30
25	27.5	30	32.5	35	37.5
30	33	36	39	42	45
35	38.5	42	45.5	49	52.5
40	44	48	52	56	60
50	55	60	65	70	75

Fuel Savings, gallons per 100k mile.

MPG	10%	20%	30%	40%	50%
10	909	1,667	2,308	2,857	3,333
15	606	1,111	1,538	1,905	2,222
20	455	833	1,154	1,429	1,667
25	364	667	923	1,143	1,333
30	303	556	769	952	1,111
35	260	476	659	816	952
40	227	417	577	714	833
50	182	333	462	571	667

Money Saved, per 100k mile @ $3.50/gallon fuel.

MPG	10%	20%	30%	40%	50%
10	$3,182	$5,833	$8,077	$10,000	$11,667
15	$2,121	$3,889	$5,385	$6,667	$7,778
20	$1,591	$2,917	$4,038	$5,000	$5,833
25	$1,273	$2,333	$3,231	$4,000	$4,667
30	$1,061	$1,944	$2,692	$3,333	$3,889
35	$909	$1,667	$2,308	$2,857	$3,333
40	$795	$1,458	$2,019	$2,500	$2,917
50	$636	$1,167	$1,615	$2,000	$2,333

Maximum Cost for 2:1 Payback.

MPG	10%	20%	30%	40%	50%
10	$1,591	$2,917	$4,038	$5,000	$5,833
15	$1,061	$1,944	$2,692	$3,333	$3,889
20	$795	$1,458	$2,019	$2,500	$2,917
25	$636	$1,167	$1,615	$2,000	$2,333
30	$530	$972	$1,346	$1,667	$1,944
35	$455	$833	$1,154	$1,429	$1,667
40	$398	$729	$1,010	$1,250	$1,458
50	$318	$583	$808	$1,000	$1,167