Gas mileage (MPG) Source Data

Running average from 0 miles (7/10/08): 46.25 mpg
Running average from 5,300 miles (7/10/08): 46.47 mpg

Date	Odo	Miles	Amount (gal)	Displayed Mileage (mpg)	Actual Mileage (mpg)	Remarks	Miles after “E”
2008
7/10	61,637	352.3	7.145	47.4	49.31	80s-90s; Mostly hwy: Bethlehem, NH; R/T; A/C
7/1	61,285	425.4	8.905	50.6	47.77	80s-90s; Guilderland, NY; R/T; A/C	12
6/26	60,860	434.3	8.718	48.9	49.82	60s-95; Local driving; A/C	4.9
6/13	60,425	386.5	7.555	46.1	51.16	60s-95; Local driving; A/C
5/29	60,039	391.1	9.302	48.3	42.04	40s-70s; Local and hwy driving; A/C	37.6
5/16	59,648	300.1	5.836	48.3	51.42	40s-70s; Local and hwy driving; little A/C
4/18	59,347	379.2	7.888	47	48.07	20s-high 60s; Local and hwy driving; 2 days of some A/
4/8	58,968	385.1	9.345	44.2	41.21	20s-50s; Local and hwy driving	27.4
3/24	58,583	350.6	8.569	43.7	40.91	20s-40s; Local and hwy driving	12.8
3/15	58,232	323.6	7.389	44.2	43.79	20s-40s; R/T: Springfield, MA; Local and hwy driving	33.6
3/12	57,909	246.8	5.229	45.4	47.2	20s-40s; Local and hwy driving
3/6	57,662	293.2	6.547	43.5	44.78	10s-40s; Local and hwy driving
2/28	57,369	285	7.77	42	36.68	Zero-30s; Local and hwy driving from Rutland, VT; local driving
2/17	57,084	294.7	6.119	44.1	48.16	Zero-20s; Local and hwy driving to Saratoga Springs, NY, to Rutland, VT
2/14	56,789	232.3	5.02	40.5	46.27	Zero-20s; Local and hwy driving
2/4	56,556	401.2	10.583	44.8	37.91	Zero-high 30s; Local and hwy driving; gas tank may have been overfilled	70.3
1/26	56,155	236.9	6.532	41.7	36.27	Zero-high 20s; Local and hwy driving
1/21	55,918	371.4	7.67	43.6	48.42	Zero-high 20s; Local and hwy driving	37.3
1/11	55,547	284.8	6.602	47.1	43.14	Zero-high 20s; Local and hwy driving
1/5	55,262	278.3	6.582	41.3	42.28	10s-20s; Local and hwy driving
2007
12/22	54,984	205.2	5.817	38.8	35.28	Teens-30s; Local and hwy driving
12/13	54,778	334	7.45	42.9	44.83	20s-30s; Local and hwy driving	2.7
12/5	54,444	332.7	7.78	41.4	42.76	20s-40s; Local and hwy driving
11/24	54,111	299.1	7.765	44.3	38.52	30s-40s; Local and hwy driving (fill-up by gas attendant)
11/14	53,812	390	7.986	47.1	48.84	30s-50s; Local and hwy driving (est. miles btwn fillups)
10/30	53,422	508.9	8.715	48.1	48.43	60s-70s: Hwy driving, Nyack, NY; R/T. (This entry includes partial and full fillup.)	123
10/29	52,913	425.3	8.891	50.8	47.83	30s-70s; Local and hwy driving; some with A/C	56.9
10/17	52,488	445.8	8.723	50.0	51.11	50s-70s; Local and hwy driving; some with A/C	42.6
10/6	52,042	385.1	8.498	48.5	45.32	50s-70s; Local and hwy driving; some with A/C	10.9
9/28	51,656	305.1	5.65	46.8	54.0	70s-80s; Lake George, NY, area; R/T; A/C
9/21	51,351	370.3	8.48	47.5	43.67	70s-80s; Hwy driving from Summit, NJ; A/C	24.9
9/14	50,981	428.4	8.782	48.3	48.78	70s-80s; Hwy driving to Summit, NJ; A/C	&22.6
9/7	50,553	423.3	8.939	47.1	47.35	80s-90s; Local driving, A/C	25.9
8/28	50,129	445.6	10.275	47.7	43.37	80s-90s; Quechee, VT, Portsmouth, NH; plus local and hwy driving, A/C	72.8
8/22	49,684	438.2	8.206	48.9	53.4	80s-90s; Killington, VT: Local and hwy driving, A/C	49.6
8/10	49,245	193.6	5.29	42.5	36.6	80s-90s; Local driving, A/C
8/1	49,052	359.8	7.391	45.8	48.68	80s-90s; Local driving, A/C
7/17	48,692	481.9	9.795	49.6	49.2	80s+; Local and hwy driving; A/C	75.7
7/11	48,210	454.2	9.934	46.3	45.72	80s+; Local and hwy driving; A/C	25.2
7/5	47,756	328.2	7.468	46.9	43.95	80s+; Local and hwy driving; A/C
6/25	47,427	405.7	7.59	52	53.45	70s-80s; Hwy driving R/T Guilderland, NY; A/C
6/21	47,022	246.9	5.053	48.1	48.86	70s: Hwy driving R/T Providence, RI; A/C
6/18	46,775	390	8.53	48	45.72	70s-80s; Local and hwy driving; A/C
6/7	46,385	421.1	9.259	48.1	45.48	70s; Local and hwy driving; A/C	53.1
5/23	45,963	241.7	5.21	45.9	46.39	40s-70s; Local and hwy driving; A/C
5/17	45,772	377.9	7.248	49	52.14	30s-70s; Mostly local driving
5/5	45,344	314.6	6.782	46.6	46.39	30s-70s; Mostly local driving
4/29	45,029	426.1	9.113	46.1	46.76	50s to 70s; to NYC and 2/3rds back	15.8
4/20	44,603	352.6	8.626	43.7	40.88	30s-60s; Local and hwy driving	29.2
4/13	44,250	254	5.944	45.0	42.73	30s-50s; Local and hwy driving
4/6	43,996	336.3	6.632	45.7	50.71	20s-50s; Local and hwy driving
3/29	43,660	419.6	10.013	46.5	41.91	20s-50s; Local and hwy driving	88
3/19	43,240	341.7	8.5	41.3	40.2	20s-40s; Local and hwy driving	8.5
2/13	42,898	394.9	9.263	41.1	42.63	10s-20s; Local and hwy driving	64.8
2/4	42,503	334.5	8.426	43.0	39.7	10s-30s; Local and hwy driving	11.9
1/25	42,169	306.6	7.309	43.6	41.95	20s-30s; Local and hwy driving	0.3
1/17	41,862	323.0	7.231	42.6	44.67	20s-40s; Local and hwy driving	9.4
1/6	41,539	315.0	7.806	44.4	40.35	20s-40s; Local and hwy driving	6
2006
12/30	41,224	236.0	4.98	43.6	47.39	30s-40s; Local and hwy driving
12/18	40,988	422.3	9.21	45.7	45.85	30s-60s; Local and hwy driving	84
12/6	40,566	345.8	8.730	44.2	39.61	30s-60s; Local and hwy driving	18.1
11/22	40,220	233.8	4.251	46.9	55	30s-60s; Local and hwy driving
11/9	39,986	423.1	8.946	47.5	47.29	40s-60s; Local and hwy driving	68.8
11/4	39,563	307.9	7.43	45.1	41.44	40s-60s; Local and hwy driving
10/19	39,255	302.9	6.23	47.4	48.62	40s-70s; Local and hwy driving
10/9	38,952	510.3	11.569	48.5	44.11	From CT; A/C (partial + full tank; 46.7 mpg for last 133 mi.)
10/5	38,442	396.5	5.575	48.4	51.64	To CT (and local CT driving); A/C
9/25	38,154	396.5	8.064	48.3	49.17	Local and hwy driving; A/C
9/15	37,757	445.2	9.007	47.1	49.43	Local and hwy driving; A/C	26.5
9/4	37,312	377.7	8.503	48.1	44.42	From NJ, plus local driving; A/C	9.2
8/28	36,934	372.9	7.575	50.1	49.23	To NJ; A/C
8/16	36,561	423.2	9.071	47.3	46.65	Local and hwy driving; A/C	33.9
7/29	36,138	465.1	9.867	47.3	47.14	Local and hwy driving; A/C	63.7
7/12	35,673	433.9	8.530	49	50.87	From Potsdam, NY; A/C
7/7	35,239	373.9	8.9	47.1	42.01	To Potsdam, NY; A/C
7/4	34,865	434.1	8.007	48.8	54.22	Hwy; A/C
6/27	34,431	469.5	10.287	49.2	45.64	80s; hwy from Guilderland, NY	39.9
6/23	33,961	252.8	5.018	47.9	50.38	80s; hwy to Guilderland, NY
6/16	33,708	362.8	7.677	48.4	38.82	60s to 80s; local and hwy driving
6/12	33,346	425.7	9.677	47.2	50.69	From NJ, plus local driving	51.8
6/5	32,920	352.3	6.95	46.4	43.99	To NJ
5/30	32,567	343.6	8.851	44	47.26	60s to 70s; mostly local driving	13.8
4/11	32,224	385.4	7.279	48.1	52.95	40s to 70s; local and hwy driving
4/19	31,838	366.2	8.615	46.8	42.51	30s to high 60s; local and hwy driving
4/3	31,472	334.1	7.856	45.2	42.53	0 to 50s; mostly local driving	10.9
3/15	31,138	394.2	8.879	47.6	44.4	0 to 40s; local and hwy driving	45.4
3/3	30,744	323.8	7.624	43.1	42.47	0 to 30s; local and hwy driving	11.5
2/10	30,420	382.1	8.496	45.1	44.97	30s to 40s; (fast!) hwy from LI to Nyack, NY, to home+	~30
2/4	30,038	425.8	9.241	46.2	46.08	30s to 40s; hwy to NYC/LI	82.2
2/1	29,612	322	7.865	43	40.94	Below freezing; local and hwy driving
1/14	22,290	364.1	8.483	47.3	42.92	Below freezing; local and hwy driving	12.7
1/5	28,926	333.3	7.729	42.9	43.12	Below freezing; local and hwy driving	30.1
2005
12/21	28,593	353.3	8.378	43	42.17	Freezing; local and hwy driving	69.4
12/5	28,239	345.5	8.077	45.3	42.78	30s to 70s; local and hwy driving	28
11/22	27,894	245.9	5.363	45.6	45.85	40s to 70s; local and hwy driving
11/13	27,648	321.5	7.248	47.6	44.36	40s to 70s; local and hwy driving
11/5	27,326	322.6	6.826	47	47.26	40s to 70s; local and hwy driving
10/21	27,004	361.2	7.64	47.3	47.28	50s to 70s; local and hwy driving	31.6
10/10	26,642	452.3	9.06	54.4	49.92	50s to 70s; local and hwy driving	12
9/26	29,190	487.1	9.531	52.6	51.11	70s and 80s; local and hwy driving; A/C	70.8
9/14	25,703	454.3	7.79	52.8	58.32	Hot (>90s) & humid; hwy & rural hwy driving (MA, coastal NH, ME); A/C
9/2	25,248	399.8	8.65	52	46.22	Hot (>90s) & humid; hwy & rural hwy driving (From Cooperstown; MA); A/C
8/30	24,849	476.7	9.524	51.4	50.05	Hot (>90s) & humid; hwy & rural hwy driving (MA; to Cooperstown); A/C; sta attd filled tank	25.8
8/18	24,372	412.3	8.371	50.3	49.25	Hot (>90s) & humid; hwy & rural hwy driving; A/C	9.5
8/13	23,959	411.3	9.703	52.3	42.39	Hot (>90s) & humid; hwy & rural hwy driving; A/C	54.7
8/9	23,548	495.9	8.337	51.5	59.48	Hot (>90s) & humid; hwy driving; touring; A/C; tank not to “full”	27.0
7/30	23,052	431.5	8.394	51.5	51.41	Hot (>90s) & humid; local and hwy driving; A/C	27.0
7/16	22,621	472.2	9.452	48.3	49.96	Hot (>90s) & humid; local and hwy driving; A/C	19.4
7/9	22,148	457.7	9.756	49.9	46.91	70s through 90s; local and hwy driving; A/C	48.9
6/29	21,691	405.4	8.125	51.1	49.9	Rural hwy driving; R/T Guilderland, NY, across VT; 80s to 90s; A/C
6/24	21,285	374.4	7.205	50.8	51.96	80s and 90s; rural hwy driving; A/C
6/15	20,911	387.1	8.609	45.6	44.96	70s and 80s; local and hwy driving; A/C	15.9
6/9	20,524	485.3	9.765	51.9	49.7	70s and 80s; local and hwy driving; A/C	?
6/1	20,038	449.4	8.731	49.4	51.47	70s and 80s; local and hwy driving; A/C
5/20	19,589	460.6	9.804	49.7	46.98	50s to 70s; some highway driving	53.4
5/7	19,128	379.8	8.0	50.1	47.48	50s to 70s; some highway driving
4/27	18,748	388.1	7.667	50.3	50.62	Days: 30s to 60s; nights: 40s; some highway driving
4/18	18,360	469.5	9.335	50.8	50.29	Days: 30s to 60s; nights: 20s and 30s; some highway driving	67.5
4/4	17,890	428.6	8.851	50.2	48.42	30s to 40s; some highway driving	42.4
3/26	17,462	363.9	7.505	49.5	48.49	30s to 40s; some highway driving
3/16	17,098	379.5	8.813	45.7	43.06	30s to 40s; about half of this is highway driving	45.4
3/4	16,718	306.3	6.797	46.7	45.06	Teens and 20s. Some snow
2/25	16,412	310.8	7.714	44.7	40.29	Well below zero at night; teens during the day. Some snow.	9.6
2/11	16,101	343.3	7.181	46.1	47.81	Well below zero at night; teens during the day. Snow.	0.5
2/2	15,758	333.7	7.601	44.0	43.9	Well below zero at night; teens during the day. Snow.	27.9
1/19	15,424	345.4	8.463	40.9	40.81	Well below zero at night; teens during the day. Snow.	60.4
1/5	15,078	257	5.797	47.5	44.33	Below freezing temperatures. Some snow.
1/1	14,821	310.1	7.188	44.2	43.14	Below freezing temperatures. Some snow.	7.8
2004
12/16	14,511	426.9	9.2	46.3	46.4	Below freezing temperatures	74.9
12/7	14,084	323.6	7.493	45.5	43.19	First snowfall, followed by freezing drizzles	40.6
11/27	13,761	357.0	8.41	45.1	42.45	Getting colder, day (40s) and night (freezing and subfreezing)	72.6
11/23	13,404	306.5	5.953	47.3	51.49	Getting colder, day (40s) and night (freezing and subfreezing)
11/12	13,097	413.3	9.412	45.9	48.62	Subfreezing evenings	63.2
11/1	12,684	397.1	8.168	48.8	43.91	Subfreezing evenings	2.6
10/24	12,287	472.5	9.521	50.2	49.63	Getting cooler, nights and days: 40s to 70s	66.8
9/26	11,814	460.0	9.782	48.5	47.03	Local, some rural/super hwy; A/C. Day temps dropping to the 70s.	59.1
9/18	11,354	432.1	8.433	49.5	51.24	Local, some rural/super hwy; A/C
9/8	10,922	411.8	8.866	48.5	46.45	Local, some rural/super hwy; A/C	11.8
8/21	10,510	423.6	8.481	49.2	49.95	Local, some rural/super hwy; A/C	34.4
8/8	10,086	469.7	10.258	49.9	45.79	Rural/super hwy driving (mostly); mid 80s/mid 90s; A/C	46.7
8/1	9,617	485.7	9.923	51.3	48.95	Rural/super hwy and local driving; high 80s/mid 90s; A/C	79.1
7/24	9,131	516.6	9.273	53.5	55.71	Rural/super hwy and local driving; high 80s; A/C	24.5
7/18	8,614	407.4	8.25	52.5	49.38	Mostly Auburn-->Cooperstown, NY, across VT (guessed disp'd mileage)	2.8
7/13	8,207	467.3	9.297	51.5	50.26	Rural (mostly)/super hwy and local driving; ~80º A/C	71.5
7/4	7,739	319.3	7.945	53.8	40.19	Rural/super hwy and local driving; mid 80s; A/C	19.5
7/2	7,420	423.1	6.704	50.4	63.11	Rural/super hwy and local driving; mid 80s; A/C
6/27	6,997	459.6	8.337	52.0	55.13	Rural “hwy” to NY, across VT; upper 70s
6/16	6,537	480.0	10.106	48.3	47.50	Hwy driving. Weather in the 80s; A/C	7.6
6/7	6,057	435.5	10.03	50.3	43.42	Warm weather. Some A/C.	46.8
5/30	5,622	307.8	5.478	50.7	56.19	Warm weather. Some A/C.
5/26	5,314	430.6	10.024	48.1	42.95	Possible mileage: lots of standing around with car on, and A/C	24.2
5/15	4,883	419.5	8.726	48.9	48.07	Decidedly 70s, some 80s, two 90+ days (yuk!)
5/8	4,464	467.7	9.726	49.0	48.09	Mostly between 50º and 60º	40.5
4/28	3,996	433.9	9.180	47.9	47.27	Mostly around 45º	58.7
4/9	3,562	425.1	8.746	48.9	48.61	Mostly between 37º and 40º	32.8
4/3	3,137	369.7	8.786	43.3	42.08	37º±4º; lots of hwy driving	17.8
3/29	2,767	487.2	~10.935	46.8	44.55	32º-47º; Ran out of gas!	104.2
3/19	2,280	422.8	10.247	43.0	41.26	Below freezing	71.0
3/8	1,857	454.6	9.586	48.4	47.42	~37º	93.6
2/26	1,402	418.8	9.383	44.7	44.63	Warming still: 37º to ~41º
2/20	984	395.5	9.562	42.3	41.36	Warming! ~30º	48.0
2/5	588	324.7	8.772	39.8	37.02	Cold: <20º	32.3
1/22	263	263	7.895	35.8	33.31	Cold: <20º

Note: The Prius displays overall gas mileage until reset. (I reset the display after each tankful.) Or, your trusty calculator can display the gas mileage by dividing the total miles between tank fill-ups by the amount of gas to fill the tank. Hence the two columns: “Displayed Mileage (mpg)” and “Actual Mileage (mpg),” respectively. Why the difference between the two calculations? It's more than “slide rule error.” See estimating empty and displayed versus actual mileage.

Note 2: According to the EPA: 61 mpg city; 51 mpg highway. According to Car and Driver and Consumer Reports: 42 mpg to 44 mpg, respectively.