My Baby Is Drinking Gas 2 Fast .

[birdii]

I can fill up the tank to the max and let it run down almost dry (53 liters) and still I cant get good mpg like other members… the most I’ve gotten was little over 230miles… I average 210-225 on a tank…

What other parts should be changed for better fuel economy?

This what I did so far since I bought my car (5 months ago)

Auto 97 GST

Changed All Belts + Timing Belt
Engine Flush
Started Using Mobil 1 Synthetic Oil
Preformed Injection Cleaning
Premium Gas (91 Octane)
Transmission Flush
Radiator Flush
NGK Spark Plugs & Wires
Air Filter & Hard Pipe Intake
O2 Sensor
Upgraded To Greddy Intercooler Hard Pipe Kit
Greddy Type-S Blow Off Valve
Tire Are Properly Inflated
4 Wheel Alignment
Optima Yellow Top Battery
Don’t Have A Heavy Foot

 

[98GSXtreme07]

Wow. You did a lot of maintenance! Always good. The only thing I can suggest to you is the fuel filter. That's the only other thing I can suggest, since I think thats the last thing you could do to help your fuel economy.

 

[birdii]

i what this car to last me for a good while... so i just need to get that filter... i have never did it before but i think i also need a boost leak test... thanks

 

[crimsondragon]

Is your car running rich at all? Black smoke coming out of exhaust...smell of fuel, etc etc.

 

[birdii]

Is your car running rich at all? Black smoke coming out of exhaust...smell of fuel, etc etc.

not sure... but sometimes when i park in the garage after driving... the garage has this odd smell... my other car (99 NT) never put out this kind of smell before...

 

[crimsondragon]

I'm thinking it could be possibly something with the ECU and it's dumping more fuel in than it should. Check that there are no leaks along the FPR line, return line, around the fuel rail, etc. Check the line from the FPR to the IM, the one which you normally should tap the boost gauge to. Make sure there are no small leaks.

 

[DougR]

Get some form of tuning capabilitie and a wideband.. This will get you a substantial MPG increase with the correct tune.
I noticed you didnt mention a boost leak test. Even the smallest leak will cause poor Fuel economy. while you are doing the test Zip tie Every hose end with small black zipties to help prevent future boost leaks andvacume leaks.

Look into the benifits of Xylene, tyolene and acetone. These require carefull mixing to get the best benifits, but they work Really well!

Also, alil more costly. but a Water Injection kit will Completly Clean the insides of the engines intake track. This in itself will improve MPG. probly not by mutch. but then again, noone ever uses WI for MPG, only for the performance benifits. so who's to say you cant squeeze another 5MPG from it..
WI will make even the nastyest buildup in motors come clean in a few hundred miles. To the point of Shiny bare metal!

O and make shure you didnt over tighten your belts.. they are a HUGE source of frictional power loss.

 

[birdii]

wow lots of reading and things to try out thx.... i had my belts and timing done by the dealer...

 

[spawn87]

well i had the same problem with my gst but when i took close attention to the problem it was cause i have a heavy foot on tha gas...perhaps your just gasing to much but thats just me.

 

[TheWanderer]

If you didn't already do it, try testing your FPR and make sure it is functioning. If it doesn't work properly, replace it. Relatively cheap fix, it runs for about 45 to 50 USD I had the same problem with my car burning way rich and having poor MPG. Changed the air filter, fuel filter, and FPR, now it runs great, with way better MPG.

I have also found that using 93 octane with a good octane booster, like NoS with MMT (the black bottle one) works great, and will increase power along with fuel economy. I went about 500 miles round trip on a single tank this way (from Reading PA to Clearfield PA). It also will clean your fuel system out while driving. Can't beat that for about 12 USD a bottle. Make sure it is the racing formula in the black bottle though, the blue bottle stuff really is crappo.... Red Line fuel system cleaner also works quite well, a bottle of it is enough to treat about 2 tanks of fuel. A bit more pricey, around 15 USD for a 32 oz bottle....

Good luck and hope this helps

Edit: one more thing you could look into would be Nitrogen filled tires. It keeps your tires filled to the proper pressure longer and makes for lighter tires i believe (don't quote me on that last part, not entirely sure. need to research it again)

 

[myeagleneedmods]

how many miles does your car have? Because I heard from a friend who knows his way around cars that if you switch to synthetic after 70k mi. or so, the synthetic will actually start eating away at your gaskets. I didn't believe him at first but now I am starting to notice a few more leaks then usual. I get about 230 on a full tank of premium, but thats because my foot is a little heavy.

 

[blueninteytwo]

no, no truth to the "switching to synthetic eats your seals"... if your seals leak after switching to synthetic, they were shot already, and your engine was basically being held together by dirt.

i switched to synthetic in my car fine.....

 

[DougR]

no, no truth to the "switching to synthetic eats your seals"... if your seals leak after switching to synthetic, they were shot already, and your engine was basically being held together by dirt.

i switched to synthetic in my car fine.....

There lies the Truth. Syntec oil's contain a Detergent. that Cleans the interior of your Engine.
Thus uncovering existing leaks that was clogged by dirt and buildup.

By switching to a syntec. You rip off bandades and uncover the Real problem.


The oil in itself is far superior to castor based oil's, USE it and fix you'r leaks. never think twice about Syntec. It Works!

 

[myeagleneedmods]

There lies the Truth. Syntec oil's contain a Detergent. that Cleans the interior of your Engine.
Thus uncovering existing leaks that was clogged by dirt and buildup.

By switching to a syntec. You rip off bandades and uncover the Real problem.


The oil in itself is far superior to castor based oil's, USE it and fix you'r leaks. never think twice about Syntec. It Works!

Well, then I guess I got a lot of seals to replace

 

[knochgoon24]

Many oils, both conventional and synthetic, contain detergents. Just check the bottles.

 

[Defiant]

"Miles per tank" is meaningless.