Maybe an anti-performance question, but here goes

N

Neilster

Guest
For those of us who commute everyday and contend with high gas prices, I've been wondering what if any, fuel savings might be gained by changing the rearend to a less aggressive ratio. I fully confess my ignorance on this. I don't know if it would realistic. I just love this car and am looking at ways to squeeze some more economy of it without too much cost. Maybe a dumb question and I'm not offended if the answer is... That's a really dumb question :D
 
RE: Maybe an anti-performance question, but here goes

Best mpg I have seen from my 97 LSC is 27.4 on the highway. My 94 base got up to 30.8. axle ratios are 3.27:1 on the LSC, and 3.07:1 on the 94. So, up to a point, a higher ratio can help. BUT higher can hurt you if you have a heavy foot.
 
RE: Maybe an anti-performance question, but here goes

I seemed to have better highway mileage on my '94 as well. I was hoping at the time I bought the '98 LSC that the mpg would be a bit better. Alas, it was not. One of the differences being the rear ratio. Probably not worth the hassel and cost. Seems to me, it decreased again somewhat when I changed the plugs. Something tells me I should revisit this as well.
 
RE: Maybe an anti-performance question, but here goes

Try pulling the octane adjust plug?
 
RE: Maybe an anti-performance question, but here goes

excuse me but what is the octane adjust plug???? I thought i knew a lot about cars but i've never heard of such .. do you mean replace the O2 sensor?

speaking about gas mileage .. here are the numbers for my 95 mk8.

Instant gas mileage:
I get about 8-10 MPG under steady (VERY LIGHT) acceleration. The speed of which would be considered normal from 0-45mph with a POlice officer right behind you.

I can see as high as 45-49mpg when coasting down from 45mph.

Average gas mileage:
My average is currently at 13.5mpg, but I have a semi-heavy foot at times (can't get over how nice this car sounds), and commute through a lot of traffic lights 24 miles every day.

I'm wondering if i should try replacing the O2 sensors for better mileage ... as my car throws no code but the 111 "happy" code :)
 
RE: Maybe an anti-performance question, but here goes

I believe 'Driller' was suggesting (pull the octane adj. plug) to use a lower octane fuel to lower your overall fuel costs. I believe the gen2 is a 'smart' car and will retard timimg to kill 'pinging' from low octane fuel. Some feel that the higher octane gives better mpg - a milage log would prove it one way or the other.

cigar51
98 LSC 60K
 
RE: Maybe an anti-performance question, but here goes

well I know the gen1 has knock sensors that turn down the timing to stop knocking (caused by low octane fuel)

so your saying gen2 has an octane sensor or something? and thats what adjusts the timing?

I think I just need a clear definition
 
RE: Maybe an anti-performance question, but here goes

There is a 2 pin connector that has a bridge plugged into it. You pull the 'octane adjust plug' and timing is retarded I think by 2 degrees.

On my '93 it is connector C177 under the plastic drivers side strut cover. It has DG(Dark Green?) and GY/R(Gray with Red stripe) wires.

The manual...

Octane Adjust Plug
The PCM measures the voltage drop across the Octane Adjust Plug and uses this information to modify ignition spark advance.

FWIW, my tuner wanted me to pull the plug while at the track to see if any performance increase or decrease would show up.

I've heard others who pull the plug to retard timing when using nitrous to lessen the chance of detonation.

If you hear the engine pinging, you can pull this plug to retard timing, but that may be relevant only for SOHC engines as the DOHC has knock sensors which will cause the PCM to automatically reduce timing.
 
RE: Maybe an anti-performance question, but here goes

Your exhaust system is the best place to save gas mileage, as is your custom chip which will be needed after your exhaust. I believe Ponyfreak got upwards of 30mpg back and forth to the track, while running 12's when he would race it.
 
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