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I've owned my car for 6 months. I noticed I was filling up more but didn't seem to mind until I started recorded gas trips.
I went from 30 mpg to 20 mpg. Same route, same driving style.
The only difference I could find was a failing speedo/odo and the usage of Magic Mystery Oil.
I thought for sure it was just the failed odometer. I wasn't getting as many miles because it wasn't tracking accurately so I thought for sure that was it. Well I had a week of no odo/speed issues and still recorded 20mpg.
Next up is Magic Mystery Oil or a sudden failed component. I've never used MMO on this car, but I have used it to help keep fuel systems clean for others. I've been adding 4 oz to a tank.
Is there anything that can explain a sudden drop? Could plugs do that? No CEL minus the known speedo issue, but it's VERY intermittent.
If you didn't start recording your mileage until after you started noticing it dropping, how do you know you were getting 30 mpg before? You don't mention what your route and driving styles are, but unless you were driving like a little old lady almost exclusively on the highway at 60-65mph, you were very unlikely to actually be getting 30 mpg.
20 mpg is normal for combined highway/city driving; you might do a little better if you drive more highway than city. If you're not sure if the odometer is working properly, then hard to be sure what it really is.
You can throw some Marvel Mystery Oil in there if you want, but it's not likely to do anything beneficial.
What car? The 3gen can't get 30mpg AFAIK, and the 4gen can ONLY if you do what 285exp said, empty the trunk and drive solo at 60mph on flat highways. The on board computer is not hyer-reliable.
That said, if you do see a sudden drop, and you have no CEL, then check your brakes. Jack each end in turn and try to spin each wheel, see if one is dragging. Alternatively, after a drive walk around and feel each wheel center; if it's dragging the friction should transfer quite a bit of heat to the wheel.
If you didn't start recording your mileage until after you started noticing it dropping, how do you know you were getting 30 mpg before? You don't mention what your route and driving styles are, but unless you were driving like a little old lady almost exclusively on the highway at 60-65mph, you were very unlikely to actually be getting 30 mpg.
20 mpg is normal for combined highway/city driving; you might do a little better if you drive more highway than city. If you're not sure if the odometer is working properly, then hard to be sure what it really is.
You can throw some Marvel Mystery Oil in there if you want, but it's not likely to do anything beneficial.
30MPG was based on a few things.. I moved from filling up every 3 weeks to filling up every 2 weeks. I had a long trip that put me at 30mpg early on.. otherwise it was very scientific.
Thinking more, based on what you are saying, I do think I was babying the car early on since it was new and I was just breaking it in, etc Im probably more comfortable and subconsciously driving her harder.
I'll try to be softer on the pedal and see where it goes.
30MPG was based on a few things.. I moved from filling up every 3 weeks to filling up every 2 weeks. I had a long trip that put me at 30mpg early on.. otherwise it was very scientific.
Thinking more, based on what you are saying, I do think I was babying the car early on since it was new and I was just breaking it in, etc Im probably more comfortable and subconsciously driving her harder.
I'll try to be softer on the pedal and see where it goes.
It would help to know what year ES you have, what mileage, and what kind of driving you do. If you're getting 20 mpg and it's mostly highway, you have a problem. If you're driving a mix of city and highway, 20 mpg is normal. If you're driving mostly city, then 20 mpg is very good. The important thing is to get a good baseline on what your mileage actually is, and unless your odometer is working properly that isn't going to be possible, unless you start driving with a GPS unit that can keep a log of your trips. Keep a notebook in the car and track all your miles traveled and fuel burned there. It's important to try to drive consistently, otherwise the data isn't very helpful, and you'll need to track it for several months to even out the variances. It's a waste of money to try to fix something if you don't really know if there's a problem or not, so before you start throwing dollars at it find out if you need to.
You still didn't say what year and model you have. My '02 ES300 gets 26 mpg on the freeway for my wife driving 50 miles to and from work.
Yikes. Thought I had. 97 es300. 139k. Mostly. Almost 80/20 mix hwy/city. It's a 13 Mile commuter but I do some errands. Definitely don't have a lead foot.
I'll try to keep logs, but more importantly try to get a refuel when Im almost entirely highway as I get to work. The odometer has been spotty, but not as of late. It only happens once in awhile. and I wrok around those outages when I check mileage. However, there is a CEL for it.. and another CEL may have popped up under that so I will get codes read to make sure.
Yikes. Thought I had. 97 es300. 139k. Mostly. Almost 80/20 mix hwy/city. It's a 13 Mile commuter but I do some errands. Definitely don't have a lead foot.
I'll try to keep logs, but more importantly try to get a refuel when Im almost entirely highway as I get to work. The odometer has been spotty, but not as of late. It only happens once in awhile. and I wrok around those outages when I check mileage. However, there is a CEL for it.. and another CEL may have popped up under that so I will get codes read to make sure.
The important thing is that you're going to have to either make sure your odometer is working properly or get some other method of tracking your mileage, otherwise you're just guessing what your actual fuel mileage is.
The important thing is that you're going to have to either make sure your odometer is working properly or get some other method of tracking your mileage, otherwise you're just guessing what your actual fuel mileage is.
I agree, however the issue is very infrequent and weeks/days this occurs, the data is thrown. In weeks with no issues, where I count that gas mileage, it is about 20-21. I feel like I have enough there to conclude Im definitely not getting what I should.
I could be wrong. 20-21 could be what I should get, but I would expect closer to 30 given the hwy mpg. I will take the car to autozone just in case a new CEL has popped up. I'm hoping it is an O2 sensor or possibly a air/fuel mixture sensor...
I agree, however the issue is very infrequent and weeks/days this occurs, the data is thrown. In weeks with no issues, where I count that gas mileage, it is about 20-21. I feel like I have enough there to conclude Im definitely not getting what I should.
I could be wrong. 20-21 could be what I should get, but I would expect closer to 30 given the hwy mpg. I will take the car to autozone just in case a new CEL has popped up. I'm hoping it is an O2 sensor or possibly a air/fuel mixture sensor...
I've owned my 97 ES300 since new, and I can count on one hand the number of times I got 30 mpg on a tank of fuel. At 70-75 mph, down here on the flatlands of Alabama I usually can count on 27 mpg or so for purely highway driving, probably 22-24 if 80-20 highway-city. I use mine almost exclusively for commuting to work, around 15 miles each way, about 60-40 highway/city, and I get right at 21 mpg consistently. Below is a graph of the last 3+ years. The only times it shows anywhere close to 30 is on highway only trips. Your commutes are only 15 miles, and the first 2 or 3 miles the engine hasn't warmed up and will not be at maximum efficiency, so you're probably getting in the low to mid 20's at best on those drives. Throw in some running around in town and low 20's is probably right.
In the above graph, there were a couple of semi-scientific tests, once running 93 octane E10 and another running mid-grade E0 instead of my usual 87 octane E10, each for 4 consecutive tanks full, about 1300 miles each time. Disregard any spikes, those are single readings. See if you can figure out when I was using the other fuels.
Thank you so much-- thats extremely helpful. Perhaps I was misunderstanding you but my expectation was to hit close to 30 mpg, but this helps tremendously.
Granted, I drive 60-65.. but this makes me feel better about getting 21 mpg. I think when I was getting better gas mileage, I was much lighter on the pedal since it was a new old car. Probably a bit harder on the pedal now since Im more comfortable in the car (and less patient with drivers)
Also, you run regular? I thought these took premium? I do a 90/93 unscientific blend
Thank you so much-- thats extremely helpful. Perhaps I was misunderstanding you but my expectation was to hit close to 30 mpg, but this helps tremendously.
Granted, I drive 60-65.. but this makes me feel better about getting 21 mpg. I think when I was getting better gas mileage, I was much lighter on the pedal since it was a new old car. Probably a bit harder on the pedal now since Im more comfortable in the car (and less patient with drivers)
Also, you run regular? I thought these took premium? I do a 90/93 unscientific blend
Premium is not required, it's recommended; unless you have audible knock you can run regular with no problems. The engine has a knock sensor, and as long as it's working properly there will be no damage to the engine. You will get slightly better power and mileage, but not much. I found premium gave me 3-4 % better mpg, which is probably within the measure of error, but cost significantly more than 4% more. It would cost me more per mile, so I use regular instead. Same with E0, slightly better mileage, but not enough to make up for the increase in price.
I've owned my 97 ES300 since new, and I can count on one hand the number of times I got 30 mpg on a tank of fuel. At 70-75 mph, down here on the flatlands of Alabama I usually can count on 27 mpg or so for purely highway driving, probably 22-24 if 80-20 highway-city. I use mine almost exclusively for commuting to work, around 15 miles each way, about 60-40 highway/city, and I get right at 21 mpg consistently. Below is a graph of the last 3+ years. The only times it shows anywhere close to 30 is on highway only trips. Your commutes are only 15 miles, and the first 2 or 3 miles the engine hasn't warmed up and will not be at maximum efficiency, so you're probably getting in the low to mid 20's at best on those drives. Throw in some running around in town and low 20's is probably right.
In the above graph, there were a couple of semi-scientific tests, once running 93 octane E10 and another running mid-grade E0 instead of my usual 87 octane E10, each for 4 consecutive tanks full, about 1300 miles each time. Disregard any spikes, those are single readings. See if you can figure out when I was using the other fuels.
Proof that ethyl alcohol kills gas mileage - if only we could get the damn government to understand!
04-01-16, 02:57 PM
Sudden drop in gas mileage?
