I'm turning to the HyperMilers for help here. Two tanks ago, I had a 59.5 tank and was dancing on air. I was well ahead of last year's trend and should definately have at least two - possibly three - 60+ MPG tanks this summer. But then my last tank came in at 57.5 and even then I was struggling to keep it in the 57s. No matter what I did, I could not get to 58MPG. I refilled on Friday, five days ago, and have logged 140 miles. Currently, I am showing 54.6 MPG. So just what in the Hell is going on here? Here are some things to consider and you tell me if there's any way this could be affecting anything: <blockquote> - I checked my air filter after refilling; it looked fine so I put it back. Already checked this evening that it's properly seated. - Over the weekend I drove two people 90 miles (normally it's just me and one other person carpooling to work). - I checked my tires this evening: 43/41. - I have not used the A/C much with this tank. - This evening I was getting an impression that my ICE was working too hard. When I stealth, it's fine; when I coast, it's more-or-less fine; but when I'm accelerating or maintaining speed higher than 45 MPH, it's like the car is working too hard.</blockquote> Seriously here, I'm at my wit's end. More importantly, this tank can ruin my lifetime average. What am I missing. What am I doing that's causing this?
<div class='quotetop'>QUOTE(TonyPSchaefer @ Jul 5 2006, 08:55 PM) [snapback]281799[/snapback]</div> It could be a few things: 1) Gas - they are now in full swing with the special summer formulated gas (in some areas). Did you get both tanks of gas from the same station? Maybe try a different brand. 2) Oil - when was the last time you had the oil changed? With the summer heat, the oil has to work harder...and maybe your filter is getting a little clogged. 3) Weight - that has a huge factor - even when I just carry my kids (less then 40 pounds each) I see a few MPG drop...especially in the uphill areas 4) Tires - you said you checked them in the evening...was that after a drive? Better to check them in the morning when they are at their coolest temperature (even if you had not driven for a while, the heat of the day could still have the inflation readings showing way too high). Hey, 59, 57, 54 are all still beating the EPA...but I understand...it kills me when I get a tank or two that are lower and just can't figure out why!
<div class='quotetop'>QUOTE(TonyPSchaefer @ Jul 5 2006, 08:55 PM) [snapback]281799[/snapback]</div> After many hours of computer modeling and studying old lecture notes, I'm pretty sure I've found your problem: You're driving a car that uses gasoline! As long as you keep doing that, you'll forever be saddled with gas mileage. It turns out that there is no such thing as "good" gas mileage! Sorry. As you know, I have no self control.
<div class='quotetop'>QUOTE(darelldd @ Jul 5 2006, 10:38 PM) [snapback]281845[/snapback]</div> lol darelldd, you always make me laugh!
Hi TonyP..., Same thing here. I was at 58 + for three tanks in a row. This last tank , which I am almost through now I am at 54.3 mpg. I think its gas formulation issues. Probably getting the E5 or E10 now.
<div class='quotetop'>QUOTE(donee @ Jul 6 2006, 05:45 AM) [snapback]281895[/snapback]</div> Tony, I think it's the gas too. I wish we could all get Li-Ion battery pack upgrades from Toyota and get our HOA's to approve wind turbines on our roofs. I think there may be some value to a few discussions on what is the ultimate as far as FE when it comes to tires regardless of performance. Because if you are driving for FE, your not driving like a race car driver. Also, a discussion on fluids for FE would be nice too. Until then just by trying to get the best MPG you can your on your way. I wonder what people who have old cars that can't run any Ethanol use?
Here my mpg is lower clearly because of the new gas mix with more ethanol. But don't forget temperature. If you are averaging just 5 deg colder that can make a huge difference in mpg.
I don't count myself as a hyper miler... but did find an interesting oddity most recently... For the last 10,000 miles (March - June) I typically get 52-55mpg at the pump, 53-56 on the MFD. I drive the Chicagoland tollway system 800 miles a week at a typical 60-65mph pace... It's consistant.. I'm used to it. Over the 4 day weekend, we went to Michigan, up into Canada a bit, 1100 miles round trip driving closer to 75 to 80 most of the way, got closer to 51mpg all counted (one tank down around 47) at the pump calculations.. Mileage is down, but I'm running longer and faster so I expect it to be down. Now I'm 1.5 days back into my commute, have 200 miles on this new tank and the mfd is at 59.4 which is my highest ever. Did it do something to my car to 'run the horse' so much harder on our trip? I'll see if it holds up, but it's my highest ever aside from just gassing up and getting home with 4 miles and 65mpg on the mfd.
I had a low tank in the spring that I could only attribute to head winds at about 15 MPH. It dropped my tank to 54. Also, when it's raining... forget it. I'm lucky to see 48.
TPS, Any mods, service to priapus ? Changes in weather ? Different petrol station ? You are taking about a 5% hit. A couple small things together could add up to that easy. It is the bane of the FE obsessed.
Tony, I vote with tomdeimos. We've had some cooler weather recently, just 60 degrees this morning. Also your 90 mile trip with 2 people probably was not your typical commuter route, extra weight/higher speed? Daronspicher, are you running on a tank of gas you obtained outside the Chicago area. The ethanol/additive content of gas outside our area is usually different and will give you a boost in MPG. I last filled up in Indiana June 15 and I'm at 67 MPG with half a tank to go, at least 5 MPG above where I should be. Wayne
The thing that affects my MPG the most is short trips. My daily commute is about 40 miles round trip between 35 and 55 MPH, and I was having my best tank ever with the display at 66 MPG for 180 miles. Then comes the 4 day weekend and multiple trips to the store, to the beach, taking people for a ride, etc. and I fell to 58 in no time. I finally got above 60 on this mornings commute, but the short trips will kill your MPG.
Hahaha, I wish I could even TOUCH your mileage! The best MPG I have been able to get on any tank of mine was 49.5MPG. And even that was hard to achieve. The hilly suburbs of Pittsburgh might have something to do with my terrible MPG but unfortunately there is nothing I can do about that. My heart sinks everytime I have to go uphill and my "Current MPG" drops to below 25mpg just so I can maintain the speed limit and not get honked at.
<div class='quotetop'>QUOTE(TonyPSchaefer @ Jul 5 2006, 10:55 PM) [snapback]281799[/snapback]</div> As a Prius driver, I understand your concerns over the noted FE change and those lost mpgs. However, listen to yourself. You're complaining about getting 54 mpg!
That *is* a relatively minor delta, really. So many little things can have an effect when you're riding the hairy edge in the first place. Birds poop on the roof recently? . _H*
Tony: I'm definitely not a hyper-miler, but my latest mileage ideas relate to battery temperature. The battery really seems to like being right around 80 to 90 degrees. Too cold or too hot and it's less efficient, will get used less, and therefore makes you car, in effect "less hybrid." What's your battery temp been lately? As for me, my current mpg is down a bit also. But that's because I've had fewer long drives. The long surface-road drive downtown boosts my mileage. The short drive to the grocery store kills my mileage. And frankly, I don't give a d**n! I bought the car for transportation, not as a video game to try to get the best mpg numbers. The less I drive the lower my numbers; but at the same time, the less I drive the less actual total gas I burn and the less pollution I produce.
Alright, I truly appreciate all the input. I'll try to address them in order; except for Darrel's. I very rarely deviate from the same gas station. The one I frequent (BP) is normally the lowest priced around and right on my normal commute. It's possible that they've recently changed the formulation of their gasoline. I can mark that in the "uncertain" column. I changed the oil at 20,075 miles. That was 1,400 miles ago. Just before the 59.5 MPG tank. Same oil as always, 3 quarts. No deviation. It's possible that the 90-mile trip with the passengers over the weekend was the major killer. FireEng's correct that it was not my regular route and there were frequent start/stops. I believe the A/C was on but not cranked. Oh wow, it was windy that day. Donee's confirmation of an unusual low tank average in Chicagoland has me speculating on gas formulation. *cough* *cough* Shut up, Evan! *cough* *cough* :lol: If it's temerature related then Mother Nature has some explaining to do! This morning's update: The mileage is up to 55.7 so it was an extremely good drive to get it up that much in just over 20 miles. Temperature was 65ºF and I did not use the A/C. You know, I normally do not pay much attention to the "green cars" on the consumption screen, but I remember Evan talking some time ago about wanting the fewest cars as possible. Yesterday when I got home, I had full cars on most segments with a couple having two and a couple having half. Additionally, there was a 5-minute segment in near 25MPG which is really really wrong for me. This was during a section of road 45 and 55 MPH, but I've driven it so many times now that I know 25MPG is too low. That's what prompted in my OP that the car was working too hard at speeds above 45MPH. This stretch of road is about 45 minutes into a 55-60 minute commute and I was not EV-ing prior. This morning, there were no doubles, but mostly wholes with a few halves. That's about par for the course. And yes I know: 55 MPG is nothing to sneeze at and according to the EPA it's exactly what I should be getting on highway driving. But dangit, daniel, Priapus IS a video game and I want the high score! <div align="center">59.9 is NOT 60.0!</div>
I've never seen 50. I don't know how anybody gets those big numbers. I'm stuck on 49.5 for the last two months. 90% freeway, 500 miles a week. No whining, I'm still a happy guy!
