I have a 92 RS with a 305 TBI, auto, and my mileage has really sucked as of late. I used to get around 25, but lately its gone way down, about 250-300 miles on a tank. The only mods i've done are a shift kit, k&n filter, and a flowmaster muffler, which should have helped if anything. it could be the cold weather, but it stills seems unusually bad. so if anyone has any ideas, PLEASE reply. thanks

 

lowering exhaust restriction does not improve gas mileage, it only increases power.

Extreme cold where the engine takes a long time to reach operating temperature will hurt your mileage.

you may just need a tune up or O2 sensor though.

 

Are you kidding me 250 300 miles per tank bad. Hahaha thats good as hell. If I baby my engine I get about 250 miles per tank.

 

I'm not 100% sure, but i think before my mileage went down, i was getting close to 400 mpg if i babied it. It has been a cold winter, but would it be enough to make almost 100 miles worth of difference?? Or else my gas gage is way off, i guess i really haven't figured out my mileage, just know i'm not getting near as many miles between fillups.

 

haha, I dunno 300 miles per tank is about twice as Much as Im getting.


figure thats what, 16 gallons for 300 miles, So approx 21 mpg, a little less.


a loss of 4 from your Claimed High, that could easily be Due to your driving style, change in Temp, ***** O2, fouled plugs, ect.



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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

It we be closer to 6 mpg, and my driving style really hasn't changed a whole lot. They colder weather could make a difference though, and i am about due for a tune up. I hooked it up to the OTC last night and it didn't show any codes, so i don't think its the O2 sensor, but would it be worth replacing anyways at 70,000??

 

Shift kit might "i said might" be eating a little more gas not much. I would give you car a real tune up plugs wires, fuel filter, o2 sensor, injector cleaner 44k is the best cleaner.
When its cold out we tend to let the cars warm up longer and that eats gas so you might try a inline heater. But summer is right around the corner so try the tune up.