Up until the last couple of tanks, we have averaged between 4.5 and 4.8 L/100 km per tank (49 and 52 miles per US gallon). However, the last was 5.0 and it looks like our current tank will be 5.4, which is 43 mpg. Although 43 is still pretty good, the change seems sudden and we’re a little worried. In the last couple of weeks, the average temperature here has dropped from 60s to 50s. Also, we’ve discovered that the left front tire loses pressure much faster than the other three. In your opinion, do you think these factors could be the cause of the change? Which factor is the more likely culprit, the weather or the tire?
I too have noticed a drop in MPG with cooler weather and my tires are inflated to 42-40 as they were this summer. I believe the outside temperature has a real impact due to the additional time required to heat the engine and passenger compartment. Of course, the leaking tire is contributing to the reduced mileage also.
Yup, welcome to the cold weather 'hit' club. 43 degrees here today...and rainy. My mileage is in the low 50s with that and I'm used to 58 for the area I was driving. This is normal and will get worse as the temps drop.
Marg, I'm also in Eastern Canada (although Ontario isn't really East, is it?) and have taken a substantial hit in the last week or two. It sounds like you have jumped from 4.6 to 5.4. My commute is very short, so my mileage is normally very bad, but my hit had jumped me from 5.4 up to 6.3. A hit comparable to what you are describing. This has come on so rapidly that I must ascribe it to the cold weather, as do all the other posters to this board. I guess we'll see how we do all winter in da Great White North.
Living in the tropics, I don't experienced this drop in mpgs. Just out of curiosity, do regular cars experience a similar drop or is this significantly higher for the Prius?
Me too! last tank. I think part of the problem in Colorado is oxygenated fuel (Ethanol) which must be in use by November each year. (It's good for clean air, but not MPG). It literally was like my last tank was an instant change. Nate
<div class='quotetop'>QUOTE(jamarimutt\";p=\"45232)</div> Yes, regular cars do have a drop in mileage, but probably not as much, and certainly not as noticable. If the Prius experienced a 10% decrease from 55mpg you'd have 49.5mpg. If a Camry had a 10% decrease from 25mpg it would only drop to 22.5mpg...not be as noticable.
I love this chatgroup. I can always count on getting an answer -- and often 5 or 10 -- within half a day. It's amazing. Thanks everyone for your answers. Its sad but at the same time comforting to know that we're not the only ones taking a hit these days.
Marg, I can only suggest you spend your winters out here on the Best Coast errrr West Coast. We were FCE (Far Canadian Easterners) at one time but have opted to move out here in the late 60's in preparation for owning a Prius. Gary
a couple of weeks ago I did a trip to Portland Or. and did 716Km at 4.88L per100K average and fueled down in Vancouver Wa. where they use E10 and did 711Km at 5.53L per 100K. thought it was a significant hit in mileage.
E10 is the only type of gas available in Minnesota, all year long. It's a bit irritating knowing that most everyone else (other states) can achieve higher MPG without even trying. But for our local economy and the air, it's worthwhile. As for the very noticeable drop in efficiency from the longer warm-up time, the need for a heater, denser air, the winter-formula fuel, the poor traffic conditions, I actually kind of like it... and even look forward to it! When you live in Minnesota, you grow to enjoy the dramatic seasonal changes. Having a car that makes them so much easier to deal with is great. Watching the MPG vary on the Multi-Display just like the weather does outside is quite entertaining. And being able to maintain MPG in the low 40's while everyone else is struggling to get around 20 is a pure delight. All that gas being wasted by those engines running because they don't have the ability to shut themselves off is sad, especially when they are so much larger than a hybrid requires. Spring is an incredible experience. When your MPG finally climbs above 50 again, you shout with joy. Knowing that it will remain there (for me, anyway) the entire duration of the warm season is fantastic. But when it comes down to what's truely exciting, it's the unknown that the upcoming next snowfall or coldspell will bring. Today is the beginning of Winter #5 for me. The temperature dropped below freezing this evening... and it promises to keep getting colder ...then will stay there for what will seem like forever. Prius is really "cool" in the cold! Look forward to it.
Ahhh.. yes... Winter. I feel you guys. It's getting cold here too. Today it was down to the Mid 70s. 8) Whooo! Go SoCal!
Marg, all the "yeah it's expected" comments are fine and I think I am starting to see the effect as well. But I would also closely check that left front tire. If it is losing pressure much more quickly than the other 3 you either have a nail or a bad tire to rim seal. Given the age of the car, I would think it is most likely the former.
yep Frank, E10 has been the only gas you can buy in WA for years. i think they mandated the fuel in 1988 or 89. i believe we were one of the first states to do so. originally it was just the I-5 corridor that required it, but that was changed to statewide several years ago. my lifetime average is still 54+ mpg though so i aint complaining.
Well, bruceha_2000, you were right. My husband took the car to the dealer today and indeed there was a nail in that right front tire. My husband and I both think that we wouldn't have spotted the problem as quickly in our old Mazda. The problem with the tire was not easy to see with the naked eye. The the instant feedback provided by the MFD and a sudden change in our fuel economy numbers prompted us to do a little investigation. Yay Prius! Thanks again, folks, for your opinions on this issue.
Here in Manitoba I've noticed quite a difference running Mohawk Ethanol and regular unleaded: 5.3 l per 100km on Ethanol vs 4.7-4.9 l per 100km. That works out to about a 4 MPG difference. In Canada, we also have to deal with MMT in regular unleaded, as it appears the Ethyl Corp has substantial influence over the Canadian government. So I have the choice of minimizing my MMT use by running Ethanol and losing fuel economy, or taking the chance that regular unleaded with MMT will eventually damage my oxygen sensors and catalytic converters. In Ontario, the Toronto area uses oxygenated fuels in winter to help reduce emissions. Not sure about other areas of Canada.
Methylcyclopentadienyl manganese tricarbonyl. Does that clear things up? :wink: It's a fuel additive -- an octane enhancer. There are concerns that the manganese in this substance, which is not biogradable, will get into the atmosphere, accumulate in the soil and air over time and just kinda stay there. Some folks think that too much manganese in our systems can impair speech and movement. The stuff is supposed to be bad for cars, too. It's no longer used in most US gasoline, but it still present in most Canadian gas. Here's an article on it. http://www.canadiandriver.com/articles/jk/020821.htm