how many GIII owners are getting over 60MPG?

It seems that 60mpg + drivers are not using AC very much? My V w/atp doesn't get over 50 mpg, no matter how hard I try. I guess it must be my lead foot + 100% AC(set at 74) in the summer months!

 

As fall approaches I'm probably going to see the big drop as usual. But since about April I've been exceeding 65 mpg calculated. Mostly city driving, tires at 40 psi all the way around, ECO mode always, minimal A/C use. I'm fortunate in that I drive the same route every day so I can anticipate stop signs and seldom have to come to a full stop. I use my Scangauge II for more accurate, instant feedback (this really helps on the hiway). My lifetime average is now over 55 for nearly 30,000 miles (calculated), that will drop back over winter but it is 1 mpg higher than last fall, maybe because of OEM tires being at about their optimum.

 

Are your tire pressures up? You have the 17" wheels, right? If so that would drop mpg a bit.

As for AC, we've found that setting it 2-3 degrees below the outside temp improves comfort a lot without affecting mpg much if at all, at least up to 90F outside temps. A lot of the comfort of AC comes from the dehumidification rather than the temp drop, and you get dehumidification as long as the AC is kicking on. If I get used to a cold temp it's tough to crank the temp up, but if I just start out at a higher temp setting I'm fine. Obviously dressing lighter (shorts, T-shirt/short-sleeved shirt, sandals) will also help if that is possible - after all, that's what I'd like to be wearing anyhow when I get out of the car on a hot day.

 

Aha, so all these tanks were with a tailwind?:

That's impressive, how did you manage that?

Seriously, worrying about round trips vs one-way, uphill/downhill, headwinds/tailwinds gets a bit silly when one is talking about full tanks. For that matter, round trips are no guarantee that there isn't say still air on the trip out and a raging tailwind on the trip back. To me, mpg on any run >100 miles is interesting info.

 

Current tank is at 62.3 (HSI), with 630 miles on the tank. Was as high as 62.8. This just might be my second 700+ mile tank. Have to go into work today, which always amazes me with the MPG difference between going in and coming home. Going in always has incredibly higher MPG than coming home, regardless of season or weather. Over 35 miles, there is a 350 foot elevation drop going in to work. It doesn't seem like that would make a difference but it sure does, consistently over 2 years. I have 33,000 miles on the car.

 

There is about a 500 foot drop on the Mass Pike between Worcester and Boston, and I almost always see amazing mpg's on that ca. 44 mile stretch. In either car. I suspect it has a lot to do with how that drop is distributed. Short steeper uphills followed by long gradual downhills seem to get me the best mpg. I also suspect that the prevailing winds may be from the west, i.e., tailwinds.

While the mpg's one gets there certainly are fun (last year I got 136mpg in the Insight-I on the segment from Worcester to the Natick rest area!!*), I don't consider them characteristic.

* = 28 miles, mild tailwind, humid late summer day, barely breathing, jaw dropped

 

During our vacation, Sept. 3-5, 2011, I received the highest MPG's ever. Fillup in LaGrande Oegon to Wallowa Lake in northeastern Oregon. Drove to Imnaha and fished and we caught quite a few nice trout in those streams.

Temps ranged from low 50's to 94 degrees. Returned 3 days later to the same gas station in LaGrande Oregon and fillup up.

428.9 miles / 6.823 gal's / calculated 62.860 mpg

Vehicle gross weight was probably about 3600 lbs or so, my wife and myself with all the luggage etc.

 

I mostly use car for urban and suburban-30km trips.
Since Jan.2010 my overall average is around 62 mpg.
Good goin' guys.

 

I can easily do 60 MPG on the MFD which is actually 57 mpg calc'd. But as for doing 60 MPG calc'd, it requires what I would describe as a lot of effort on my part.

I had achieved it for the span of two tanks a few fillups ago but I haven't gotten back there because it got a lot hotter lately..

And yes I did have to turn off the A/C occasionally to get to 60 mpg calc'd, but the weather was much cooler back then.

I did it to see what my "best tank" could be but I think I've settled upon 56-57 mpg calc'd as maximizing fuel efficiency while minimizing frustration (for me).

55 mpg is 10% more than EPA. 60 mpg is 20% more than EPA but about 3 to 4 times harder to achieve than 55 mpg (subjectively).

 

This summer I've been averaging almost exactly 60 mi/gal (3.9 L/100 km). My average is slowly coming down after a terrible winter of not knowing the proper warmup cycle of the car.

-Iain

 

To me, even 100 miles is too short if it is not a round trip. Even at that substantial distance, downhill assist can help produce results such as this:


Full tank distances, > 500 miles, sharply reduce this illusion.

 

Were you fill up is important. Thats why I filled up at the same station so there is no elavation error.

If I filled up at 3,000 feet and than at 1,500 feet It would be snap to get a true 60 mpg.

alfon

 

I can achieve 60 mpg (calculated) anytime I want ..... but not in normal, everyday driving. If you,( or I) drive 35-45 mph, steady on the gas and brake pedal, no rian, you will get close to 65 mpg. I have done it three times .... once when my G3 was new, and twice recently (45k on the meter) in Yellowstone NP where the speed limit is 45 mph. Drive all day not exceeding 45 mph ... you are there. Acknowledged that few owners drive at that speed for extended period of time.

In normal, city/highway driving, normally with one trip over a mountain pass, A/C on, but driving a steady 35-45 in town and not exceeding 73 mph on the highway, I consistently get right at 52 mpg (calculated) .... in fact my average for all fuel consumption thus far in 2011 is 52.1 mpg. It was lower in the winter, but has increased in the spring and summer.

Speed, uneven driving habits, standing water on the higheay, headwind, excess load, and low tire pressure and what reduces fuel efficiency. Pump error is a factor, as is A/C ... but they are too minor to calculate IMHO.

 

The operative wording was "interesting info". To me your shot of the display is interesting data because it shows how sensitive mpg's are to grade. If it's clearly stated as a downhill (or downwind) run, there should be no illusions that it would be typical mpg in daily usage.

That segment I posted from Worcester to Natick is part of a longer 140-mile trip from my home in CT to Medford, MA, a run I often make. Both my home and Medford are more or less at sea level. As a result of running that segment, I understand better that the favorable terrain on the segment from Worcester to Medford has a surprisingly large effect, increasing my trip average mpg (in that car) by 10-15mpg when I get to Medford. My mpg getting from home to Worcester is lower because (a) I'm averaging out (amortizing) the warmup gas usage and (b) the rolling terrain trends overall uphill. The differences are not at all apparent visually as you drive the route. This info is relevant in a general way for ANY car. I saw similar results in the Prius and my old Subaru, though obviously the actual numbers differ.

IOW, this is about info that is (a) interesting, (b) useful, and (c) fun. This ain't the MPG Olympics.

[edit] Did some research. Where I get on I-90 is actually in Auburn, MA, not Worcester. Auburn is variously listed at 501 to 603 feet elevation, for convenience let's say 580 feet. Natick is listed at 180 feet. So that's 400 feet in not quite 28 miles, or about 14 feet per mile. So this certainly isn't the Rockies or the Sierras. It's hard to believe that such a slight downgrade could explain such a large jump in mpg. I have to think that the exact contour of the route and the mild tailwind were larger factors.

 

From my rule of thumb for elevation change in a Prius, I'd expect that elevation change over that distance to boost a flat-land 60 mpg up to almost 66 mpg when descending. Since you saw a greater boost, it seems likely that tailwind was also a factor.

My pictured result above included a 5000 foot net descent, much of it wasted in B mode compression braking after the traction battery filled.

 

My last fillup was August 30, 2011. I travelled 695 miles on 10.178 gallons of E10 87 octane ( I was trying to get over 700 miles on one tank but I got spooked that gas prices might shoot up so I quit early). The MFD read 71.7 mpg - but I calculated it was only 68.26 mpg. Tire pressure was at 47 psi front, 45 psi rear using stock Yokohama Avid S33 ( I had not monitored the tire pressure, and later I found out the pressue had dropped slightly over the last 30 days). The operational driving temperatures from 8/1-30/11 was from 70f to 90f. I'm was hypermiling most of the time. I'm was using AC less than 10% of the time.

The fillup before that was on August 1, 2011. I travelled 658 miles on 9.39 gallons of E10 87 octane. The MFD read 70.3 mpg - I calculated my FE at 70.07 mpg. The tire pressure was at 50 psi front and 48 psi rear using stock Yokohama Avid S33. The operational driving temperatures from 7/11/11 to 8/1/11 was from 80f to 100f -definitely hot. I'm was using AC less than 10% of the time.

I've been teaching myself hypermiling for the last 15 months with my MPGs improving gradually. My first 1000 miles - I was only getting 55 mpg. In the Summer of 2010, I was averaging about 60 mpg (calculated at the pump). In the Winter of 2010-2011, my mileage dropped to 52 mpg (calculated at the pump) despite overinflating the tires to psi 44/42 and 100% grill blocking. In the Summer of 2011, my overall fuel efficiency improved to 65 mpg (calculated at the pump) with 70 mpg represents my best performance sofar for a given tank of gas. Overall for the last 15000 miles that I've driven I'm getting about 60 mpg. I'm using a ScangaugeII to currently monitor engine temperature, battery state of charge, gallons per hour used, and ICE RPM. On my 15 mile commute, I go to work downhill and come home uphill - so I get better MPGs going to work ( best is 83 mpg/15 miles downhill) than going home ( best 78 mpg/15 miles uphill). Last year my best commute using the same route was 67 mpg/15 miles downhill and 62 mpg/15 uphill. I believe the FE improvement is due to increasing the tire pressure from 44/42 to 50/48 AND to a hypermiling technique called Driving with Load (DWL) that I'm started doing more often this year. However, my overall summertime MPG is less because it represents the inclusion of short trips, non-hypermiling emergency trips, and shuttling kids with the AC - which causes the Prius MPG to drop down to 50 mpg. Fyi - Going over the max sidewall tire pressure setting at front 50psi and rear 48psi only helps fuel efficiency when the roads are dry. When the roads are wet or not smooth, I get the same FE or better with a lower tire pressure, e.g. front 44psi /rear 42 psi. Here in DC - we are getting alot of rain and the driving temperatures have drop to 60f to 70f so its taking longer for the engine too warmup to its most efficient operating temperature ( >180F) which is causing the MPG to drop off a bit. I'm thinking of dropping my tire pressure down and putting on the grill blocking early this year.

On the cleanmpg.com mileage logs for the gen3 Prius, I've noticed that some of the very high Mileage logs for the Prius are for special fuel efficiency marathons were the Prius is driven over 150 to 700 mile at one time which mitigates the initial warmup penalty that causes the MPGs to drop. Another tactic was to not drive the Prius during the winter to avoid driving the car at lower temperatures and thus logging lower MPGs. If gasoline prices go up over $6/gallon - I might consider installing an engine block heater for the winter...


hope this helps

Walter Lee
2010 Toyota Prius III, Blue Ribbon/Dark Grey, oem floormats
Yokohama Avid S33 ( recently set to front 46 psi / rear 44 psi
because of Tropical Storm Lee)
ScangaugeII ( AVG/FwT, RPM, SoC, GPH)
0% grill blocking

Odeometer +15200 miles, overall 60 mpg
MD/DC/NoVA Metro Area

 

Good idea. We use one year 'round. Good for mileage, the engine, your comfort in winter. The part's maybe $60, but installed is pricey, so I'd suggest to ask a few dealerships, if possible. It's doable your self, anything is, but not that easy. We just got the dealership to do it, and I just sorted out the cord through the front bumper a bit.

 

...and with another car pushing the Prius from the rear...