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Though my highway mileage remains good, 30 MPG average, I'm concerned that lately, my gas mileage has dropped for regular around town driving. I have no codes showing up, my air filter was changed a few months ago, and have done all my regular maintenance for 13 years now since I've owned the car including regular synthetic oil changes. I'm now at 260K miles and am wondering if that much mileage could have any bearing on this. I only use Top Tier gasoline like Costco (93 of course) because of their detergent additives. Might it be Costco's gas?
where you've kept up with maintenance with your vehicle but still seem to be dropping fuel mileage...
just a thought...and it may or may not be the culprit....
as the winter fuel still holds flame in Feb.
I have been having MPG issues too. Only mine is cause my car rips with the cold weather!
Jokes aside, I have heard also that winter blends affect mileage. Also take into consideration that you probably have the heat on which will in return consume more fuel. At least it feels like it does, similar to running the A/C on hot summer days.
Try running the car with heat on full blast, and without it. Report back. I am not sure if it is true or not but as I stated it sure seems to use more fuel.
Unless you turn off the A/C manually, the compressor may also run with the heat. I usually manually disable the A/C unless I have a fogging issue.
My notes for MPG suffering during winter months:
- idle to warm the car
- winter fuel blends
- check your tire pressure
My winter MPG tends to go down a decent amount which I mostly attribute to the increased idle times to warm the car. When it is garaged, no extra warm-up times. However if it gets left out overnight or even after-work, it may sit there for 5 minutes idling to warm up.
Because it's somewhat irrelevant. He's noticed a change, that's all the info we need.
Since winter hit, I'm averaging 21 mpg where in the summer I pull 29. My worst this winter for one tank was 16. AC manually turned off, and the car is garaged at home and at work. This year seems to be pretty bad for mpg, and I'm also going to Costco (illuminati).
Winter Gasoline has a different mix compared to Summer Gasoline. You will see a slight difference in MPG (always lower than your Summer average)
Keep in mind, your engine intake air temp is cooler vs summer. Winter cold air is denser than Summer hot air. True to any car performance enthusiasts, the theory of having a cold air intake (CAI) is to produce more power. While the engine does produce more power when introduced to cold/cooler air, it will cause a drop in MPG. It's only slight, maybe 1-2 mpg less.
Another thing to keep in mind. Let's say it's 20 degrees outside, you let your vehicle warm up, so now you are idling longer which also causes carbon to build up (Very small amount) so now your MPG takes a very small hit. Your tires, yes they are super cold in the winter season but they are no longer starting out at 32 psi. Rule of thumb is, for every 10 degrees temperature drop, that's 1 psi less in the tire. So you drive on the highway now your tires are warming up, they might end up reaching 30-60 degrees higher now you have more air in the tires. Let's say you don't drive on the highway and only take local roads, the tires will never reach those temps, so you might be under the recommended PSI. When you take your vehicle in for service, the technician is suppose to check fill the tire pressures. So if you had them set in November, but now it's 40 degrees colder in January, your fuel economy will suffer.
The engine fluids are thicker and cooler vs in the summer time. As the vehicle is warming up, your engine oil is harder to work with til it's warmed up. That will also cause a slight drop in MPG. In the mornings, it's still very dark out. You have your lights on, heat on max, fan on max, radio on ect.. There's more of an electrical usage vs in the summer time. The charging system is being called for high electrical load. It bumps up the idle to keep the charging system functioning correctly. This will also cause a slight drop in MPG. Also keep in mind about the colder air is denser statement. It also causes more of a aerodynamic drag. Lastly, driving in snow, ice and slush, since you have limited traction and grip your mpg also suffers. I remember back in school the teachers saying slippage in snow = less efficient fuel economy due to RPM's always jumping when traction is lost. Again, very small loss in MPG. If you add all of this up, you will see the difference in winter driving vs summer driving.
I can get 30+ max in the summertime if I drive 65 or less on the turnpike. Tried to do a similar speed today and I was getting 25-26. There were lights spotatically though so its not a fair test, but yeah in general in the winter time I lose a few mpg.
cruised at 53-55mph during the weekend, average speed = about 30mph...hit 30mpg, but decreased as soon as i got into the city with stop and go
Hit 30 MPG because your TL spending most of the time sitting in garage, Mine get about 18-20 in real traffic time. On the freeway I am able to get up to 32 MPG with the cruise set at 75 MPH, the Base able get up to 34 MPG at 75 MPH set cruise.
Hit 30 MPG because your TL spending most of the time sitting in garage, Mine get about 18-20 in real traffic time. On the freeway I am able to get up to 32 MPG with the cruise set at 75 MPH, the Base able get up to 34 MPG at 75 MPH set cruise.
On my base 6spd I can get it to read a consistant 34mpg if I reset the trip monitor while cruising on the highway and keeping the lighest throttle at 64mph, but this doesnt matter because it is instantly negated by any traffic and the fact that I have to drive a good ten minutes to get to the turnpike. Because of that for me the absolute best I can do is ~28mpg and I have to try really hard to get that. Really most of the time I get 18/25/22 city/highway/combined.
jeez, how are you guys getting 30+ mpg. im only getting 22 average city/hwy even after air filter, seafoam, water pump, and an oil change. getting around 275 before light comes on
jeez, how are you guys getting 30+ mpg. im only getting 22 average city/hwy even after air filter, seafoam, water pump, and an oil change. getting around 275 before light comes on
Sounds pretty normal to me. If you look at my post above that is right in line with what I am getting. When most people are saying 30+ they are talking strictly about their highway mileage. And my highway mileage can suck if I am on the gas a lot. I have to hyper mile it to get more than 32mpg.
Just came back from a 1 hour trip (each way) upstate NY. I normally use a ¼ of a tank round trip to this location. Today however, I used ½ a tank for the exact same trip, yet my highway mileage itself stays around 29-30 MPG. No, the heat nor the defroster was on. Am I loosing it, or is the car?
it could be the fuel that your local gas station having also. I swear before my TL got like 27-28 MPG but bam all the sudden I was able to get 30 MPG, I drove the same way with cruise set at 75 mph.
jeez, how are you guys getting 30+ mpg. im only getting 22 average city/hwy even after air filter, seafoam, water pump, and an oil change. getting around 275 before light comes on
I average 21-22 as well and easily get 32 on the freeway...............
Because it's somewhat irrelevant. He's noticed a change, that's all the info we need.
Since winter hit, I'm averaging 21 mpg where in the summer I pull 29. My worst this winter for one tank was 16. AC manually turned off, and the car is garaged at home and at work. This year seems to be pretty bad for mpg, and I'm also going to Costco (illuminati).
That's an insane difference. I've owned this car for nine years and have never had a winter/summer variance of more than 1-2 mpg. I'm in upstate NY. You must do a serious majority of highway driving at low rpms to average 29.
Been using Costco 93. Guess I'll try a couple of tanks of Shell V-Power and see what happens.
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Costco actually is a pretty good tier gas, both of my TL been filled with nothing but V-Power. Well until my wife decide to put Cheveron premium in it for the extra cost.
Just came back from a 1 hour trip (each way) upstate NY. I normally use a ¼ of a tank round trip to this location. Today however, I used ½ a tank for the exact same trip, yet my highway mileage itself stays around 29-30 MPG. No, the heat nor the defroster was on. Am I loosing it, or is the car?
HELP !!!
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I think you're stuck on it's gasoline alone, however it's not. When was the last time you got a carbon cleaning service done? When was the last time you changed your PCV valve? When was the last time you inspected the condition of the tires, including tire pressure? When was the last time plugs and a valve adjustment was done? There's a lot of factors to take into consideration. It's not just a single issue that's causing the fuel economy to drop. I provided a lengthy description on why in the Winter season your fuel economy would suffer. Unless we get into deep detailed description on your TL's maintenance records, it's only a GUESS on why your MPG is suffering. You do have 260K, the vehicle is worn, the engine clearances aren't tight, the fuel injectors might be less efficient than they were new. You get the point? Changing gas station may not really fix the issue, but it's worth a shot. Keep us posted if you switch gas stations. Maybe adding a bottle of ISO HEET injector cleaner and water remover into the tank, your MPG might improve? A bottle is enough to clear out the tank of any water left behind from gasoline.
I think you're stuck on it's gasoline alone, however it's not. When was the last time you got a carbon cleaning service done? When was the last time you changed your PCV valve? When was the last time you inspected the condition of the tires, including tire pressure? When was the last time plugs and a valve adjustment was done? There's a lot of factors to take into consideration. It's not just a single issue that's causing the fuel economy to drop. I provided a lengthy description on why in the Winter season your fuel economy would suffer. Unless we get into deep detailed description on your TL's maintenance records, it's only a GUESS on why your MPG is suffering. You do have 260K, the vehicle is worn, the engine clearances aren't tight, the fuel injectors might be less efficient than they were new. You get the point? Changing gas station may not really fix the issue, but it's worth a shot. Keep us posted if you switch gas stations. Maybe adding a bottle of ISO HEET injector cleaner and water remover into the tank, your MPG might improve? A bottle is enough to clear out the tank of any water left behind from gasoline.
I get the vehicle is worn thing, but the maintenance history of this car is exemplary! Carbon cleaning service hasn't been done in ages as Paul (our Star mechanic in Northern NJ) says as long as I use top tier gas, everything should stay clean. PCV valve was changed, valve adjustment, and plugs were done a year and a half ago. I'm making the same trip upstate NY today and I'll throw in a bottle of ISO HEET in before I go. I also filled up with Exxon/Mobil yesterday, so stay tuned ..........
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02-15-2017, 09:40 AM
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