I made my first trip from Bakersfield to Vegas with mods. This is a bi-monthly trip for me. What was done was:

One step colder plugs

Removed spare, jack, stock sub, and boat anchor

Gutted third cat

I set cruise to 70 as usual. First thing I noticed was climbing the hills near Tehachapi. Anyone who knows this area knows these hills are steep. The car usually kicks down to 4th gear for most of the incline with the occasional 3rd gear downshift. Surprisingly it pulled the hills in 5th the whole time, locking and unlocking the convertor clutch but never downshifting. This was more than I was expecting.

Made it to Vegas with 1/8 more gas than usual. I haven't filled up to calculate mileage yet but I can already tell it's considerably higher.

Looks like the colder plugs have helped with my surging issues in Vegas. There's some normal power loss but none of the surging and weird behavior like it did before the plugs.

Picking up a drop-in K&N to see if I can bump mileage a little more. I can't wait for the trip back down to Bakersfield again. I've hit 34mpg before stock so I can't wait to see what is possible now.

For what it's worth, car seems to pull harder, especially at higher speeds.

 

how many miles did you have on the car? I think that the factory plugs may have been fouled up by something if the change of plugs helped out. I would run some seafoam thru the system with the old plugs to clean out the motor entirely.

 

It does have 90% steady state freeway miles which promotes carbon buildup. Even though I post on here about flooring it, I think EVERY time I've floored it I've posted about it. It really has been driven very easy. It has 48K on it.

I should've done the seafoam before I did the plugs but totally forgot. It does run fine at sealevel both with the old plugs and new plugs. Old plugs looked good with a little more carbon around the outside diameter than I would've thought. I was actually surprised at the carbon because my old GN which shouldn't burn as clean (it is fuel injected though) when run on non-leaded gas, the plugs look like they have never been used. They come out perfectly clean.

 

Well, you probably see this comment coming from a mile away....

It ain't the colder plugs....

It's the weight reduction giving you the extra performance.

 

^ lol

 

truth...

 

whooaa fill me in on these plugs please

 

Personally, I'd leave the spare tire in the car. I'd hate to think what I'd do if I got a flat drving through the Mojave desert. That's a long walk.

 

x2

 

Can taking out the spare and jack really do that much? I doubt it...The spare weights like 30lbs...the jack probably weighs around 5lbs..

its probably from the third cat IMO.

 

I only took the spare and jack out because the shop that installed my amp put a screw through the spare. It will eventually go back in. In it's place I have a supersized can of fix a flat and a tire patch kit.

The weight reduction did way more than I thought. I'm very in touch with this car. I notice every little difference. I was about to buy new shocks because the suspension was getting a little soft. By removing the boat anchor, stock sub, tire and jack, and a couple lbs off the convertor, the ride is quite a bit stiffer and new shocks are not needed. It feels more nimble. I had to go back over Inaccurate's posts on weight reduction to make sure I wasn't going crazy and imagining things. It really makes more of a difference than you would imagine.

Filled the tank today. Mileage came out to almost 33mpg which is 3mpg better than my average for that direction. It's usually ~3mpg better going the other way. My drop in K&N filter didn't come in today but should be here tomorrow. Can't wait to do the same trip in two weeks and see what kind of mileage I can get. If I decide to keep the car, the pre-cats are going too.

I'm positive the colder plugs will improve gas mileage around town in Vegas. With the surging gone, the computer is no longer retarding timing and I'm giving it way less gas for a given acceleration.

As for the convertor, it can only help mileage. Might not be much but it has to help a little. After I deleted it, the only difference I think I could feel performance wise was on a 3rd and 4th gear pull on the freeway. Couldn't tell a difference around town. On a 14 second car you really can't feel less than a 10hp difference.