DIY: Fuel Economy Gauge for your car (to lower your car's fuel consumption)

**ghosthunter** · April 15th, 2012 01:50 PM

Originally Posted by chuaed

pwede rin mag install ng air-fuel ratio meter...

Air

True. But if your car does not have a factory installed oxygen sensor, it is going to get expensive. You will need to buy a air/fuel ratio meter with oxygen sensor and find a place to have the oxygen sensor installed properly and another place to install the meter and wire it up. (yup I have done that already). If your car does have a factory installed oxygen sensor, if its a single wire type, readings from it may be inaccurate if it is in the wind path of the radiator fans.

After all that, the A/F meter is only good for telling you if your engine is running properly or to help you tune your engine on the go. It will not tell you if your driving habits result in good, average or poor fuel economy.

**BratPAQ** · April 27th, 2012 05:19 AM

question, we have a honda city AT with FC reading for the last 10 seconds, i use that to learn how to step on the gas. now we have a new vios AT but has no FC reading. I got 2 question.

1. The vios is only 2 days old, would installing this to the intake manifold void the warranty?

2. What I learn (how to step on the gas) from our honda with FC reading can be applied to vios and will result on better fc? Or different car = different behavior?

**ghosthunter** · April 27th, 2012 09:41 AM

Originally Posted by BratPAQ

question, we have a honda city AT with FC reading for the last 10 seconds, i use that to learn how to step on the gas. now we have a new vios AT but has no FC reading. I got 2 question.

1. The vios is only 2 days old, would installing this to the intake manifold void the warranty?

2. What I learn (how to step on the gas) from our honda with FC reading can be applied to vios and will result on better fc? Or different car = different behavior?

Knowing Toyota, if they find your modification, they can void the warranty but generally they will hardly notice an extra vacuum tube tapped into the engine's intake manifold. Just try to find an unused port on the intake manifold before resorting to using a "T" fitting to tap into an existing vacuum line.

Example is my ASX. It was only a month old and I had a UNICHIP installed. No one from Mitsu really notices it.

BUT if something does go wrong with your engine (something very remote from happening with a new car), best to disconnect and hide the vacuum tube (to the gauge) before having the engine checked.

As for learning how to step on the gas based on the vacuum gauge vs the fuel economy meter, it should be the same. In fact, the vacuum gauge would give you a faster feedback.

**neyzon** · May 6th, 2012 07:27 PM

Have anyone heard about K&N’s replacement air filters? A friend of mine told me there's a lot of good feed back regarding this filters as they increase your HP & FC.

Here's the image;

K&N 33-2392 Drop in Filter

OK kaya tu?

**ghosthunter** · May 6th, 2012 10:15 PM

Originally Posted by neyzon

Have anyone heard about K&N’s replacement air filters? A friend of mine told me there's a lot of good feed back regarding this filters as they increase your HP & FC.

Here's the image;

K&N 33-2392 Drop in Filter

OK kaya tu?

K&N filters are ok but the gains would be small and will hardly be noticed based on "feel".

**neyzon** · May 8th, 2012 04:49 PM

I got a noob question. Is there a way to determine if my fuel gauge is not working properly? Sorry new on cars. I got my 1st car few months ago Mitsubishi Lancer Sedan 1997 Model 1.3 engine Carb type. I just noticed recently my gauge seems to fall down quickly to the red line & I just normally used it from home to office w/c is about 28KM back & forth. At 1st I thought it was my driving habits but I been following fuel economy tips but its doing the same. What's weird is I noticed that I can still reach up to 60+ Km at the red line w/out refueling. As far as I know when you reach the red line you have roughly 2-3 liters pa sa tank so I thought I shouldn't be able to last up to 60Km w/ just 3 liters. Pls correct me if I'm wrong.

**ghosthunter** · May 8th, 2012 07:47 PM

Originally Posted by neyzon

I got a noob question. Is there a way to determine if my fuel gauge is not working properly? Sorry new on cars. I got my 1st car few months ago Mitsubishi Lancer Sedan 1997 Model 1.3 engine Carb type. I just noticed recently my gauge seems to fall down quickly to the red line & I just normally used it from home to office w/c is about 28KM back & forth. At 1st I thought it was my driving habits but I been following fuel economy tips but its doing the same. What's weird is I noticed that I can still reach up to 60+ Km at the red line w/out refueling. As far as I know when you reach the red line you have roughly 2-3 liters pa sa tank so I thought I shouldn't be able to last up to 60Km w/ just 3 liters. Pls correct me if I'm wrong.

Our cars have a "reserve" fuel amount even after the fuel gauge reads empty. So depending how you drive, you can go 20 km or further on the reserve amount.

As for the fuel guage itself, the quickest way is to ask your friendly mechanic to pull out the fuel float from your gas tank and check if the position of the float corresponds to the indication on the fuel meter. At the same time, you can check the condition of the float's resistor. If it looks corroded, it might be better to have it replaced.

BTW, in some cars, the fuel guage drops to "E" quickly when it gets below a certain point because of the shape of the fuel tank may not be the same from top to bottom. The tank might be smaller/narrower at the bottom.

**neyzon** · May 8th, 2012 09:02 PM

Originally Posted by ghosthunter

Our cars have a "reserve" fuel amount even after the fuel gauge reads empty. So depending how you drive, you can go 20 km or further on the reserve amount.

As for the fuel guage itself, the quickest way is to ask your friendly mechanic to pull out the fuel float from your gas tank and check if the position of the float corresponds to the indication on the fuel meter. At the same time, you can check the condition of the float's resistor. If it looks corroded, it might be better to have it replaced.

BTW, in some cars, the fuel guage drops to "E" quickly when it gets below a certain point because of the shape of the fuel tank may not be the same from top to bottom. The tank might be smaller/narrower at the bottom.

Thanks a lot! I'll take a note of that. I'm really having difficulty determining my car's fc.

**ghosthunter** · May 8th, 2012 09:16 PM

Originally Posted by neyzon

Thanks a lot! I'll take a note of that. I'm really having difficulty determining my car's fc.

The best way to determine any car's FC is from full tank to full tank and noting from your odometer or tripmeter how far you drove until you filled up the 2nd time. Then divide the kilometers by the number of liters of fuel.

The fuel gauge is not that accurate.