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Gas mileage has dropped!

13014 Views 24 Replies 14 Participants Last post by  FiveFive
Been awhile since my last post here...hope everyone had a great Holiday....I am posting here in hopes of getting some help/advice/guidance from you guys. About a month ago I replaced the air filter in my 2008 XB Limited Edition....the car has 20,000+/- miles on it now and since I replaced the air filter, my gas mileage has really sucked. It has gone from 27-28 down to 23-24 mpg....I can't for the life of me figure out why changing the air filter would have any bearing on reducing the mpg....I haven't replaced the plugs in the car, they are still the factory ones....would this cause the drastic reduction in mpg? I mean the car really didn't get that good of a mpg before, but it was better than the 23-24 that I am getting can anyone offer any suggestions as to why the mpg has dropped so I need to change the plugs and if so, what would you recommend and the gap setting would help.....I just am so confused at this point in time......I would of thought that a fresh air filter would have helped the mpg....:eek:

Thanx for any help you guys can offer me....:help:

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Hi Anita. I have a 2010 xb and have never gotten 27-28 mpg. I actually get 22-23 mpg and that was at stock air filter and exhaust.
Colder weather will cause a loss in MPG. I don't know where you live, so I can't say for sure. I doubt that a new air filter would cause the loss of MPG.
I'd be grateful! I struggle to keep my mpg's at 22. I'm nearly always in the 20-21 range. The owner of the car before me managed to squeeze 24.5 mpg out of it. By the way, all of these readings are from the onboard mpg calculator, and I have the stock exhaust and intake as well.
Another significant factor is the CRAP gas they are selling right now. It is cut with ethanol (moonshine), which burns less efficiently than gasoline. 10% ethanol in your fuel itself could give a notable drop, esp. in cars not designed to run on the crap. Note: that has gone from an advertising to a warning . . .
On straight ethanol, one could expect a 40-50% drop in MPG (according to many, various reports- search google for more precise figures). Besides, your engine aren't designed for it and would overheat from trying it.

Ethanol is NOT a good thing in your engine, it's better in your belly as drink- it the more original form as moonshine. In fact, 15% gasoline is added to ethanol (to get E85), largely so people won't drink the stuff (related to tax and tax law issues).
Plus up here in the northeast they sell regionalized blends and from Oct to May the gas you buy is oxygenated meaning you get %10 less gas. even so i usually get 27-28 MPG in winter and 30+ MPG in summer.
Most likely a change in the weather or regional gasoline for changing the plugs with only 20,000 miles...don't waste your money.

Right now my onboard mpg calculator reads 21.6 mpg. Thats normal driving off a fill up last week that I've used half of now. I have heard about the crappy gas and weather factors though... but I guess I just didn't notice a difference myself.
Mine increased after I installed a t/b spacer and a drop in k&n . only 30 miles per tank but hey , i have a little more acceleration and some miles.
30 miles isn't anything to sneeze at, thats like a gallon free with every fill up :cheers:
I'm getting 22-23 mpg with daily stop-n-go traffic on PCH. Commute to work is 6 mi, 20 mins with plenty of stoplights.
I have an AEM intake with a RS 7.0 TRD exhaust on my '08 xb.
SoCal weather has been cool ... 55-65 degrees hi.

I live on Pacific Coast Highway next to a freeway offramp. Living next to the freeway makes my car get dirty super fast on the outside. I don't doubt that it's doing the same to the engine too. I've switched to a reusable cabin filter because of this.

Could it be that the MAF is already gunked up at only 20,000?

This thread got me thinking so today I talked story with a Toyota mechanic about cleaning the MAF sensor and preventive maintenance. He told me that it won't hurt my xB (at 21K) and would be a good idea for my daughter's tC (at 49K).

I bought an aerosol can of CRC MAF Cleaner from Pep Boys tonight. I'll do both cars this weekend and let you folks know if MPGs improve.
Mine is "usually" around 26.5...but I drive slow.
so i have a 08 scion xb and live in San Francisco but travel to the east bay a lot which is just 40 miles away. any recommendations to increase gas mileage
so i have a 08 scion xb and live in San Francisco but travel to the east bay a lot which is just 40 miles away. any recommendations to increase gas mileage

coast more. i drive 45 miles each way to work and now that the summer gas is starting to show up i'm getting 29 mpg according to dash...28 mpg according to gas pump.
I get 24mpg if I am lucky but I am a lead foot. Jack is right about the ethanol. I bet these cars would consistently hit 30mpg with straight reg unlead. There used to be a gas station down here that still sold it. It was more expensive, but I saw every bit of 4-6mpg more on my Blazer running it. Well worth it.
Just cleaned my air filter. Wonder if that will make a difference . . .
I have a 2011 with 1100 miles on it. The average MPG is 27.3 as of today. This is the millage I'm getting using the crappy gas. I'm located in Northeast Pa.

where at in Northeast PA Chuck? Always looking for new members in the Lehigh Valley Scikotics chapter and I know there has been some interest in a Scranton chapter.
I'm about 40 miles north of Reading, I live in Fridensburg.

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