Um...my car's been quite less fuel efficient than before..what's going on?

Maybe the brown stuff on your tires is sludge.

http://www.consumeraffairs.com/news04/2007/01/toyo...

I'm kidding about the tires.! I have no idea what color 'sludge' is or if it would some how get on your tires.

But you really need to read the article (the link, above) about the class action suit regarding Toyota engine sludge. Your vehicle is listed.

obviously this has been an ongoing problem, that has been going on for some time. But news of it has been swept under the carpet for far too long.

I have a 97 Camry, 4 cyl. Try this,

1 Change air filiter

2 Replace spark plugs if over 100K miles.

3 Get a bottle of RXP gas treatment. This treatment will get the carbon out of your engine and fuel injectors. You should feel the difference and see an increase in gas mileage immediately.

Check your air filter, fuel filter, injector, and other replaceables. If they're dirty, be sure to replace them, as they're major causes of lowered fuel economy, and if left untreated it could harm your engine quite a bit.

I think that a lot of that brown stuff we think is dirt, is actually the anti-ozonants coming to the surface of the tire. It could mean its time to replace the tires, but then again it couldn't. Make sure you're tires are properly and adequately filled. You may want to get a full-system tune up.

A 1998 car shouldn't be decreasing in fuel economy very rapidly, especially for a Toyota.

Good luck.

I undergo in ideas seeing an commercial for a Beech Bonanza years in the past that stated it burned a lot less gas on a 2 hundred mile vacation than a regularly occurring relations vehicle. Now, this became lower back interior the 60s, yet modern-day SUVs are not a lot more effective perfect than Sixties relations autos. the position I stay interior the mountains, even a 172 can decrease the go back and forth time by technique of seventy 5% if crossing levels. 12 gallons in a 172 to bypass one hundred and fifty miles direct to my figure's position, or 20 gallons to bypass three hundred miles to an same position in my truck.

Whens the last time you changed your oil? How is the air pressure in your tires? Check all filters...or have all replaced, they are inexpensive. Gas quality doesn't change between suppliers. Only grade. Though, if you live in an area where you get gas in both rural and city areas, go for the city gas, it is regulated more to be of higher quality.

Could be a few things. Fuel filter could be getting used up, cheap quality gas, clogged fuel injector. I would try getting the fuel filter changed, use a quality fuel like Sunoco, and try some fuel injector cleaner. Then see how that affects your fuel consumption.

In addition to all the above info, also get your oxygen sensor checked/replaced. Toyotas will over fuel if the exhaust sensor reads the exhaust gas levels incorrectly...

Could be a couple of things.

dirty air filter

cloged fuel filter

dirty fuel ingection system

lower pressure in the tires

blocked catylac converter

try some of these options and they could possibly help.

check the tire pressure, air filters, oil, they can reduce fuel efficiency

when was the last time you gave it a complete tune up??spark plugs,wires,distributor cap,rotor,and even added a can of injector cleaner to your gas tank?? if awhile // try this see if it doesnt get a lot better,,good luck