[QUOTE=Tollboothwilley;4776494]I think part of the reason you get such bad gas mileage is because California gas SUCKS NUTS.QUOTE]

I could see that.

 

I know Cali get the sucky 91 octane but I don't see that hurting mpg. But if they use ethanol all year, THAT would suck. Most areas only add it during the winter.

 

Its not the 91 Octane that is the problem...its the damn ethanol. At least 10% in Cali. Plus there are tons of hills...up and down up and down all the time. Its fun to drive, but sucks the gas like its a slurpee on a summer day in Phoenix.

We only have 91 octane here...and only 91 in AZ.

 

no hills to speak of where I drive (coastal So Cal - LA/OC area)

 

I live in Kansas therefore my fuel is 10% ethanol, but luckily, I can get 93 octane now. Every since they did the ethanol switch across all fuel grades, my MPGs slipped about 10% (17-18 100% city, 24-25 100% highway). I just don't see how ethanol is a viable fuel source.

 

Ethanol actually raises the octane. But it's lower BTU makes it less efficent, hence the lower mpg. But it burns cleaner so they use it in the winter to help reduce emissions.

 

So with the FD change, the speedometer is now going to be incorrect? Anyway to re-correct this? Cable driven speedos can get a different gear but I'm sure the z/g don't use cable driven speedo anymore.

 

^ Not if your tires are the same overall diameter as stock. Speedometer goes off rear wss

 

The speedo comes off of the sensor reading axle stub teeth. Changing the FD doesn't change MPH reading at all as long as you change the whole pumpkin. If you tried to reuse axle stubs you would probably have issues.

 

I'm sure they compensate for the ethanol when they do octane ratings as well...(thin out the quality of the gas because you are raising the octane via ethanol). Its not that you are getting a octane increase from the ethanol 90% 91 octane + ethanol (98 octane - guess) and getting an overall 92 ish.

I'm sure its a double damn.

 

no issues here with speedo (original pumpkin with different fd)

 

right, you didnt change pumpkins/stub axles. If you had changed pumpkins but not stub axles you would have problems from what I understand.

 

Well, you guys have convinced me to do the 3.5/vlsd swap. I hope my CC works like Toll's too, even though my G will no longer be the long distance family hauler after March when we get rid of the wife's 98 Legacy GT wagon and get a newer, far more plush late model Outback Limited. I'll admit, I have argued in the past that the 3.5 swap doesn't make much difference in the 1/4 mile as tested with my 23.5" tall drag radials (makes the effective ratio a 3.55). My car was fractionally slower ET wise and about 1.5mph slower due to the early 4th gear shift. But the 3.5 gear WITH the 23.5 DRs would bring the ratio up to a 3.75. After doing some math and factoring in the extended rev limiter of the TS ECU flash, the car could be a bit quicker in the 1/4 (possibly .2 seconds). The real benefit should be in auto-x which is what I'm more focused on now as well as nice daily driving throttle response.

 

Driveability is changed significantly. You'll love the difference across the whole power band. With increased rev -limit & transgo kit I bet you would lose .3-.4 sec in the 1/4.

i'm running 245/35/19 which are about 2% shorter than stock...effectively puts me around 3.6 FD ratio.

 

I agree as well. I wasn't expecting a phenomenal difference, but have been pleasantly surprised with the difference. I see the biggest change between 3-6000 RPMs as the car just takes off. Freeway ramps are really fun, and Dave, I think you'd see a big benefit for your Auto-X.

After 2 tanks of gas and a lot of spirited driving on a combination of freeway and city miles, my gas mileage is w/in .5 MPG (18.5) of my normal average. I have had no issues with the CC either, but I haven't tried to set it above 85.

Overall a really good bang for the buck mod if you can get a good price. I'm just curious to ride in a 3.7 swap and see if that is where I should have gone in the first place. I know OCG35 really likes his.