Gas Mileage Checklist
#16
Despite what everyone says, including the owners manual, I have gotten better mileage and performance with single electrode plugs vs dual electrodes. I had duals in and every time I started it I could hear some knock it sounded like while it sat an idled. I threw singles back in and that went away, also had better throttle response and about 1mpg increase.
#17
If I go with changing all my o2's it will be at the end if the other things dont work. When I did change one I had bought a universal denso for like 52 bucks and it seemed to work. No more CEL. I doubt that could be contributing to whats going on.
I'll pick up a bottle of lucas today and try that.
Any suggestions on sparkplugs? NGK's from autozone are fine?
I'll pick up a bottle of lucas today and try that.
Any suggestions on sparkplugs? NGK's from autozone are fine?
Are your tires properly inflated? You may want to over inflate them. Are you using snow tires?
Remember that all that money your putting into your GS like new spark plugs, O2 sensors, servicing, alignments, replacing suspension parts just to try to improve mileage is going to cost you a ton more then you will ever get back in improved mileage. Unless your car needs these things or they are due to be replaced I would not bother spending all that money in hopes of just improving gas mileage a little because it is not worth it.
#18
If you are driving in New York City you are going to get horrible gas mileage no matter what. Four cylinders get bad fuel economy in the city. There was a thread a few months ago by someone with the same problem and he tried everything but the culprit was all the stop and go driving, poor roads, short trips, and car never having a chance to warm up to proper operating temp in New York City. On the weekend drive out of the city and try driving it mostly on the highway. I am sure your mileage will drastically go up, if it doesn't then you might have a problem.
Are your tires properly inflated? You may want to over inflate them. Are you using snow tires?
Remember that all that money your putting into your GS like new spark plugs, O2 sensors, servicing, alignments, replacing suspension parts just to try to improve mileage is going to cost you a ton more then you will ever get back in improved mileage. Unless your car needs these things or they are due to be replaced I would not bother spending all that money in hopes of just improving gas mileage a little because it is not worth it.
Are your tires properly inflated? You may want to over inflate them. Are you using snow tires?
Remember that all that money your putting into your GS like new spark plugs, O2 sensors, servicing, alignments, replacing suspension parts just to try to improve mileage is going to cost you a ton more then you will ever get back in improved mileage. Unless your car needs these things or they are due to be replaced I would not bother spending all that money in hopes of just improving gas mileage a little because it is not worth it.
Tires are inflated to factory spec. No snow tires on the car.
#19
Even with highway driving i'm getting about 11-12. The plugs do need changing. Alignment is also needed since most of the front end was in crappy shape. I ended up replacing everything with the front suspension. I highly doubt the o2's need replacing.
Tires are inflated to factory spec. No snow tires on the car.
Tires are inflated to factory spec. No snow tires on the car.
#20
Despite what everyone says, including the owners manual, I have gotten better mileage and performance with single electrode plugs vs dual electrodes. I had duals in and every time I started it I could hear some knock it sounded like while it sat an idled. I threw singles back in and that went away, also had better throttle response and about 1mpg increase.
Curry, since you've already reverted back to stock wheels and cleaned out your trunk, these items should be next, in order:
-air filter
-clean maf
-clean TB
-lucas fuel system cleaner in your next tank
-spark plugs
-fuel filter
-diff fluid (yes, it does make a difference)
-o2's
-remove injectors and have them professionally cleaned/replaced
EDIT: just saw your most recent post where you say "plugs do need replacing". DUH. that'll definitely kill your mileage.
#21
If you are driving in New York City you are going to get horrible gas mileage no matter what. Four cylinders get bad fuel economy in the city. There was a thread a few months ago by someone with the same problem and he tried everything but the culprit was all the stop and go driving, poor roads, short trips, and car never having a chance to warm up to proper operating temp in New York City. On the weekend drive out of the city and try driving it mostly on the highway. I am sure your mileage will drastically go up, if it doesn't then you might have a problem.
Are your tires properly inflated? You may want to over inflate them. Are you using snow tires?
Remember that all that money your putting into your GS like new spark plugs, O2 sensors, servicing, alignments, replacing suspension parts just to try to improve mileage is going to cost you a ton more then you will ever get back in improved mileage. Unless your car needs these things or they are due to be replaced I would not bother spending all that money in hopes of just improving gas mileage a little because it is not worth it.
Are your tires properly inflated? You may want to over inflate them. Are you using snow tires?
Remember that all that money your putting into your GS like new spark plugs, O2 sensors, servicing, alignments, replacing suspension parts just to try to improve mileage is going to cost you a ton more then you will ever get back in improved mileage. Unless your car needs these things or they are due to be replaced I would not bother spending all that money in hopes of just improving gas mileage a little because it is not worth it.
Running with bad plugs makes the engine run RICH. Running too rich causes the engine to EAT piston rings. Running with bad injectors can cause the engine to run LEAN. Running too lean causes the engine to BLOW.
these cars REQUIRE regular maintenance to stay running as well as they do for as long as they do. Have you ever tried to comprehend how the self-learning ECU even works? All the tiny little variables it calculates? If airflow, fuel flow, ignition timing, or anything is even SLIGHTLY off, you're hurting the engine's performance.
#22
1mpg could be the result of deciding to wear sneakers instead of boots every day for a week.
Curry, since you've already reverted back to stock wheels and cleaned out your trunk, these items should be next, in order:
-air filter
-clean maf
-clean TB
-lucas fuel system cleaner in your next tank
-spark plugs
-fuel filter
-diff fluid (yes, it does make a difference)
-o2's
-remove injectors and have them professionally cleaned/replaced
EDIT: just saw your most recent post where you say "plugs do need replacing". DUH. that'll definitely kill your mileage.
Curry, since you've already reverted back to stock wheels and cleaned out your trunk, these items should be next, in order:
-air filter
-clean maf
-clean TB
-lucas fuel system cleaner in your next tank
-spark plugs
-fuel filter
-diff fluid (yes, it does make a difference)
-o2's
-remove injectors and have them professionally cleaned/replaced
EDIT: just saw your most recent post where you say "plugs do need replacing". DUH. that'll definitely kill your mileage.
Sorry what I meant was the plugs don't need replacing as in they have been in there forever. I recently did them but I wanted to pull them to double check them to see if anything was wrong with them. I did pull them a month ago and there was nothing wrong with them and they were gaped correctly.
#23
I didn't know about the diff fluid, thanks for the heads up on that.
Sorry what I meant was the plugs don't need replacing as in they have been in there forever. I recently did them but I wanted to pull them to double check them to see if anything was wrong with them. I did pull them a month ago and there was nothing wrong with them and they were gaped correctly.
Sorry what I meant was the plugs don't need replacing as in they have been in there forever. I recently did them but I wanted to pull them to double check them to see if anything was wrong with them. I did pull them a month ago and there was nothing wrong with them and they were gaped correctly.
I bet once you think about this, your mileage was OK until you checked the plugs (and i'm betting checked the gap with a slide gauge) and reinstalled...I'll be anxiously waiting your "Ah HAH!" momend
#24
how do you know they were gapped correctly? did you actually check the gap with a slide gauge? If so, this may be your problem. When installing plugs for these cars, you should NOT attempt to gap them.
I bet once you think about this, your mileage was OK until you checked the plugs (and i'm betting checked the gap with a slide gauge) and reinstalled...I'll be anxiously waiting your "Ah HAH!" momend
I bet once you think about this, your mileage was OK until you checked the plugs (and i'm betting checked the gap with a slide gauge) and reinstalled...I'll be anxiously waiting your "Ah HAH!" momend
#25
were they platinum? iridium? Copper? I'm pretty sure the GS300 requires ONLY iridium plugs (please correct me if I'm wrong, anyone that knows for sure).
I remember when I was on the maxima boards back in the day, those cars called for copper plugs, and some guy tried NGK iridiums and it eventually ended up blowing his headgasket (through other contributing causes of course) but still.
I remember when I was on the maxima boards back in the day, those cars called for copper plugs, and some guy tried NGK iridiums and it eventually ended up blowing his headgasket (through other contributing causes of course) but still.
#28
that's like saying I'm not going to spend the money on cleaning visits because I'll eventually have to go to the dentist to get dentures anyways.
Running with bad plugs makes the engine run RICH. Running too rich causes the engine to EAT piston rings. Running with bad injectors can cause the engine to run LEAN. Running too lean causes the engine to BLOW.
these cars REQUIRE regular maintenance to stay running as well as they do for as long as they do. Have you ever tried to comprehend how the self-learning ECU even works? All the tiny little variables it calculates? If airflow, fuel flow, ignition timing, or anything is even SLIGHTLY off, you're hurting the engine's performance.
Running with bad plugs makes the engine run RICH. Running too rich causes the engine to EAT piston rings. Running with bad injectors can cause the engine to run LEAN. Running too lean causes the engine to BLOW.
these cars REQUIRE regular maintenance to stay running as well as they do for as long as they do. Have you ever tried to comprehend how the self-learning ECU even works? All the tiny little variables it calculates? If airflow, fuel flow, ignition timing, or anything is even SLIGHTLY off, you're hurting the engine's performance.
I said don't start replacing things just to try to get better fuel economy unless they NEED to be replaced as part of regular maintenance. What I was saying is if the part is working properly and not due to be replaced then it can be a waste of money to just start replacing a bunch of parts working properly in the hopes of better fuel economy. I never said not to maintain the car or if the plugs were bad to not bother replacing them. Try rereading the post if you did not comprehend it the first time because I never said what you are eluding to.
Some people spend a ton of money to try to get better fuel economy like cold air intakes, lighter aftermarket wheels, engine cleaning kits they see on infomercials, after market spark plugs, expensive batteries(I have heard people say certain batteries give them better fuel economy), etc when none of it needs to be replaced and all they do is put a bunch of money they will never get back from better fuel economy and most of that stuff won't help fuel economy anyways and that is what I was getting at. I never said not to replace things that are in need of replacing.
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96celsior
GS - 2nd Gen (1998-2005)
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04-30-12 05:12 PM