Maybe this has already been covered, so I apologize for the redundancy. My MPG has dropped from 53 to 48.5 as the weather has cooled here in the Northeast. I have an 08 with 5500 hundred miles and this is my first cold weather experience. Is this typical? Is there a way to improve it. Thanks in advance. David
Very typical. Search EBH - Engine Block Heater and grill blocking for some ways to attenuate the cold weather hit.
Check the "Current Mileage" link in my signature. There's a chart showing the correlation between temp and mileage. It's very "statistically significant."
Indeed Tony's graph is excellent. John Fagnant's is excellent to...see it in his recent owner's summary document: John's Stuff - Toyota Prius - Owner Summary
You can improve it by doing the water temp. sensor hack ...It makes the engine think it's already warmed up.....
That sounds dangerous. Yeah, my mpg dropped by about 5 since last week when it got REALLY cold here in Philadelphia. I think I'd like to do the grill blocking. Does that thread include a FAQ for rookies like myself that shows where to buy whatever I need and exactly how to install it?
Nooah, got to Lowe's or Menards or someplace that sells foam pipe insulation. Cut the pieces in half(down the middle) then cut the length to fit in the grill slots. Cover all of the slots except for the bottom slot in the lower grill. If it's not as cool in your area as it is here, you may want to leave the bottom two open. I don't think emissions would go up since the hack doesn't do away with the S1 part of the warm-up cycle.
That sounds interesting enough for me to research, but it also sounds like it'd be a bad thing for the engine...
I got my car in Dec, 2008. So, from my very first attempts at getting above EPA FE/MPGs, I was hampered by low temps. First thing I did was get a ScanGauge, then I blocked both grills. Overtime, I came to the conclusion that temps were the largest variable on my daily commute of 14.4 mi each way, in mixed urban/hiway driving, out and back. I wanted some way to challenge my Fe/MPG skils everyday, taking the daily temps into account. I came up with this formula: Very Good Daily MPG = 60 - 1/2*(60 - air temp). On a 40 deg. day, 50 MPG for an out and back commute is the target. Note: temps in deg. F. Very rarely do I get better than the computed VGDM at temps below 40. But it's something to aim for every day, and warrants a quiet celebration when I get even close. This formula works for me in Ballamer, where temps only occasionally drop below 30 deg. F. I don't think it would be valid for the folks in Alberta who report seeing -40 deg F. That would be only 10 MPG as a Very Good Daily MPG. If a Prius was getting 10 MPGs, what would the other drivers be getting? (At below -60 the formula says that you'll get -MPGs, a concept I just can't fathom.) This suggests you might have to fiddle the formula for a different daily regime; traffic, topography, temps far below 30 deg, roads, total miles, etc. Hope this helps.
I have owned a 2008 Prius Pkg 2 with 8200 mile on it since Feb 2008. Feb - Apr I ave 48MPG. The summer I was getting near 60 MPG. Since Oct I am working hard to keep 40 MPG. I have a scan gauge II, Grill Blocking and tires at the max inflation. I even use my EV Mode switch whenever possible at lights and parking lots. My wiinter temps in the Berkshires of Western Mass are already in the 20's and will be below zero over the winter. I hope my mileage comes back up in the Spring. Still 40 MPG is pretty good to me! I did not find a mileage diffrence with cold weather grill blocking but the Prius gets to S-4 much faster with blocking thus I assume it helps even if my mileage is only at 40 MPG. At 60 MPH on a highway with blocking my engine temp runs about 10 degrees higher (194) than without blocking at (184). I do not plan on a block heater as I feel the electricity use is not worth the upgrade as I can only plug it in at night at home for a 5 mile morning commute.
I have an EBH, my tires are at 60/58, my grill is blocked. This week I had a fresh tank for my daily very short commute and around town stuff I was under 40 mpg - for the week for a total of about 60 miles or so. But today I had a long (200 mile) round trip up and over the Green Mountains and back. At the end of that trip I was up to 52 or 53 mpg for the tank so far. I'm convinced that if I drive slowly and carefully I can continue to average around 45 mpg even in the dead of winter. We'll see, but I am optimistic. I'll be thrilled with 45 mpg - ecstatic if I can do 50 mpg.
Thanks so much! It was in the 30's much of this week. I don't think it will top 50-something until April.
You may have a pleasant surprise in the next day or two. We hit 71F here this afternoon. I have a friend that lives west of Harrisburg and he usually gets the weather I get a day or so later.
Wow - that seems REALLY high. I'll have to look on mine - but what's the max PSI rating for the tire?
