geting bad gas mileage

[timmytownsend88]

ok just wondering was it is i am geting bad gas mileage i have new fuel filter, new msd ignition.. gutted cat and a 4 1/2 exhaust tip i have no cel.. i hooked up my iphone to the obd II and checked my o2 sensors and there geting voltage and working front and read i also have did the spark plug non fouler trick using two of them and drilling one of the two out please help thanks

anyone?

 

[99eclipse420]

new plugs, new air filter, premium or race gas, and Lucas fuel additives and cleaners will help a lot. You should be getting between 30-40 mpg on a full tank of gas.

 

[CanadianTalonTC]

Running premium or race gas will not do anything for you, race gas is leaded and will damage your 02 sensors.

That being said, my 02 sensor was outputting voltage, but it was not doing it correctly causing poor mileage. Can you actually read the voltage range coming out with your scanner?

Joel

 

[Anubis_4_99]

ok just wondering was it is i am geting bad gas mileage i have new fuel filter, new msd ignition.. gutted cat and a 4 1/2 exhaust tip i have no cel.. i hooked up my iphone to the obd II and checked my o2 sensors and there geting voltage and working front and read i also have did the spark plug non fouler trick using two of them and drilling one of the two out please help thanks

anyone?

So your getting bad mileage.... What kind of mileage are you getting? Could help us a little to steer you towards your problem.

@99eclipse: What are you driving that your getting 40MPG besides a honda? Cause it ain't an eclipse. Most I've ever gotten was 29MPG with a tailwind highway. And the N/T isn't even rated over 30MPG highway.

 

[99eclipse420]

On a full tank of gas I get right at 480-510 miles in my eclipse. Also Race gas has a higher octane which will clean out the fuel lines and the head, I should have mentioned to only put in about a gallon or 2 of race gas to mix with the other gas, that's my fault.

 

[Anubis_4_99]

On a full tank of gas I get right at 480-510 miles in my eclipse. Also Race gas has a higher octane which will clean out the fuel lines and the head, I should have mentioned to only put in about a gallon or 2 of race gas to mix with the other gas, that's my fault.

That's right about 30MPG, so only a couple MPG over what the N/T was rated at from the factory, i think you would be hard pressed to get 40MPG though.

 

[CanadianTalonTC]

On a full tank of gas I get right at 480-510 miles in my eclipse. Also Race gas has a higher octane which will clean out the fuel lines and the head, I should have mentioned to only put in about a gallon or 2 of race gas to mix with the other gas, that's my fault.

That is a common misconception. Higher octane does not mean higher quality, it simply resists pre-detonation more. Gasoline is an excellent cleaner itself, your fuel lines shouldn't be dirty.

Joel

 

[99eclipse420]

Not trying to start a fight but how do you get 30 mpgs for 480 miles per tank I have a 12 gallon tank 480/12=40, Im just trying to figure out your math.

 

[Anubis_4_99]

Not trying to start a fight but how do you get 30 mpgs for 480 miles per tank I have a 12 gallon tank 480/12=40, Im just trying to figure out your math.

My math is based off of the actual fuel capacity of the eclipse.

Fluid Capacities:
Oil capacity 4.3 l [4.5 qt]
Oil filter capacity 0.5 l [0.53 qt]
Coolant 7.0 l [7.4 qt]
MT Transmission fluid 2.0 l [2.1 qt]
AT Transmission fluid 8.6 l [9.1 qt]
Power Steering fluid 0.9 l [0.95 qt]
Refrigerant - R-134a (HRC-134a) 700-740 g [24.69-26.10 oz]
Fuel 64 l [16.9 gal]

 

[99gst214]

To the OP. What was the voltage reference on the o2's? At idle you should read around 0.5v at sensor 1. And sensor 1 should bounce around like crazy. Rear o2 should maintain voltage pretty steady. If your front o2 is not moving around (meaning voltage not increasing then decreasing) then I would say that is your issue.

 

[slayer450]

My math is based off of the actual fuel capacity of the eclipse.

Fluid Capacities:
Oil capacity 4.3 l [4.5 qt]
Oil filter capacity 0.5 l [0.53 qt]
Coolant 7.0 l [7.4 qt]
MT Transmission fluid 2.0 l [2.1 qt]
AT Transmission fluid 8.6 l [9.1 qt]
Power Steering fluid 0.9 l [0.95 qt]
Refrigerant - R-134a (HRC-134a) 700-740 g [24.69-26.10 oz]
Fuel 64 l [16.9 gal]

That might be the capacity but when my needle is on E I can only stuff about twelve gallons

 

[Anubis_4_99]

That might be the capacity but when my needle is on E I can only stuff about twelve gallons

I can get sixteen gallons in mine.

Still would like to know how your getting over 10MPG more then your vehicle was rated at when it was new. Let alone 16 years later.

 

[TallestHERETIC]

Are your tires in good shape? Bad tires or badly maintained tires eat up gas like nobody's business. They hopefully just need air.

When's the last time you did a full tune up? I think that gutted cat and humongous exhaust tip is the main issue here. They can make the engine run like crap, hence the poor mileage.

Since you are still N/T, just stick to regular gas. Premium has absolutley no benefit unless you are boosted. Save your money, dude.

 

[timmytownsend88]

ive just did a full tune up, just head head rebuilt last weekend.. but my rear o2 sensor doesnt read anything until i give it some gas maybe i need to drill out my non foulers a lil bit because in my state i have to have a cat, but in my case i dont so i used the non foulers to move the o2 sensor away from exhaust im sure you all know about that.. ive drove it a little over 100 miles and used a half tank of gas

 

[Colt4G63 also]

The rear O2 sensor can not affect gas milage; it's sole purpose is to test the converter.

I only get around 200 miles per tank in my 4 cyl Accord during the winter. I blame winter fuel blends, combined with remote starting my car for 15 minutes before each 4 mile trip.

In the summer I'll get 400 miles highway out of one tank.

 

[eatsleepboostin]

I agree with Anubis. There's no way an Eclipse get 40mpg. If you get around 30, that's damn good already. And why would you want to run race gas. If you want to get that kind of mileage, stick to the Hondas. Only way to get more mileage out of your dsm is make sure your engine is running healthy, up to maintenance and eeasy on the pedal.

 

[SpeedTech720]

What was changed if anything before you started getting bad gas mileage? Is anything leaking? vacuum leaks, egr, and actual fuel leaks can cause this and very simple fixes.

To the 40mpg crisis people. You can tune any car to get way better than stock mileage. If you lean it out a little under highway conditions you can get better mpg as well as non engine related factors such as tires and wheels and weight reduction and aerodynamics. Just driving 55mph instead of 85mph gets way better milage.