shrinking gas mileage

Engine oil overfilled.

Check your oil level.

 

I have an '06. It got new tires @ 30,000 miles and has dropped 3-4 MPG since. I always run my A/C on 68-70 degrees all year round so I know that's not it. I do my own servicing so that's not an issue. I believe using ethanol is lowering my MPG. I have an '08 and it's barely getting 47-48 MPG. Going from 48-35 MPG is a big drop & I have no answer on that one.

Try & think of any other changes that may have affected your MPG. Air pressure, brand of gas, etc. Hope this helps.

 

I have also noticed a dramatic drop in mpg without any change in driving pattern.
I used to get between 45 - 49 mpg and the last fillup I got just 30 mpg.
I took it to the dealers and the computers (18 or so) rweported no issues with the hybrid motor or battery.
Any advice or experience would be welcome.
Thanks.
Soyab

 

Did you get a new kind of tire, or are they the same as the originals? The original kind (Goodyear Integrity) do very well for fuel economy.

What is the tire pressure now?

 

(Off the Island here)

Still on the original Goodyear Infinity's. Pressure on the front tires are 46, rear is 44. I haven't checked it in about a month and will need to check it again. Last oil change was done at dealer (Ernie Palmer). I'm at nearly 14,000 miles on the vehicle. On the AC it's set to 76°F and isn't on constantly (I work odd schedule, therefore I get home at night and can crack the windows open at night when driving home sometimes).

Tires can be main culprit if they're at the recommended Toyota pressure versus what we know here on PC. Also, filling up at the Flash Foods stations around the county can have an effect (all have at the most, 10% ETHANOL). Remember to fill up at the A1A Gas Mart, Smile Gas Stations or the A1A Texaco in Yulee (They don't have ethanol YET).

BTW, I'm currently average 49 mpg from driving on I-95 for the first six months after I got the vehicle and driving to/from work this way. Now due to my new habit of driving to/from work in Jacksonville using US 17 and all of Jacksonville's city streets I'm going to average 51 to 53 or better if I can. (I'm in the Magnetic Grey Prius with the AQUACULTURE tag [or as the DMV lady put it, the Little Nemo tag] )

 

They put 5w30 oil and didn't overfill? I think you're seeing several effects all adding up at once. New tires and maybe lower tire pressure; even though you have the AC on the same temp I assume its much hotter there now so it works harder; maybe they are putting more ethanol in now; etc. Hopefully it still tracks straight, doesn't need an alignment? Overall comment is what a bummer!! Another thought comes to mind... have your travel patterns changed? Maybe schools out now and trips are shorter and more frequent or something like that?

 

I drive a 400h. In the past 2 months my MPG dropped by 18% When I contacted my dealer they told me of tests that showed hybrids could lose as much as 30% in mileage with using E-90.

Seems one local TV station obtained 2 Priuses and ran them both with and without E-90. In one car they lost almost 30%!

 

All that from Ethanol? Do you know if the big brand name gas stations are still Ethanol free? I lowered my oil level below the full level and the MPG picked up slightly so far. Went from 47.5 to 48.7 over 100 miles.

 

I have not been able to find any non-ethanol stations in Tampa. If someone knows of one please post.

I was getting 26.9 MPG in my 400h, now it is 23.4 MPG, which is acually a 13% reduction.

 

2 months ago I noticed a loss of mpg from 51.2 to 41.3. I get the worst mpg driving in the city. 75% of the time the you cannot take off using just the stealth mode. When you let up on the gas it feels like there is a drag. If it had a regular transmission you would think it was in 2nd instead of drive. Had it to 2 dealers and all they do is hook it up to the computer and say there is nothing wrong with it. I checked all the tangibles, oil level, tire pressure, etc: It does this whether the a/c is on or not. Any suggestions?

 

Does your gas have ethanol?

 

I found a Shell station in Tampa that is still non ethanol. After 3 tanks my mileage has slowly climbed back to 26.2 MPG.

 

I lowered the oil level below full- NO increase in milege. I just dumped some Lucas fuel injector cleaner into the tank. Will let you know if milege increases. Ever since I put new stock tires on my '06 the MPG has not returned to 54 MPG. This is most disheartening as I see no reason why it dropped.