Trying to increase gas mileage.

[garland]

I'm sitting here at work on my break putting around with the idea of increasing my gas mileage without overspending on parts to do it.

Right now the car gets about 25mpg hiway, me driving like a grandmother. I drive only 87 octane unless I'm going to the track because I drive like a grandma all the time. I did the math on the better mileage I got out of premium (28 mpg) and it didn't work out to be worth the difference in cost per mile.

Here are my current metrics, just some rough math:
25mpg now
250 miles/ 10 gallons
25.00 for 10 gallons
10 cents/mile
100/mo
1200/yr

some other nums:
28mpg: 1050/yr
30mpg: 990/yr
35mpg: 840/year
Anyway I've been putting around trying to think up some ideas on how to save $$$ on gas.

I thought about the following parts:
header $350
smaller pulley $400
lighter rims $700

The problem is they aren't worth the difference a few MPG would save me. So those are out. Now my current ideas consist of:

A) a supercharger bypass system - I'm not talking a bypass valve preventing boost buildup, but an actual pulley bypass to prevent parasitic loss.
Examples: new accessory belt minus supercharger,
swap in and out as needed.

clutch based pulley that only worked at wot
(no idea on how to implement that)

B) A bypass valve controller that would allow me to open/close the bypass valve through in cabin controls. This would allow 14psi on the track and 0psi on the freeway.

C) Be more dilligent about tire pressure. I should do this anyways.

D) Cut some weight out of the car. Like rip out all that highly necessary sound deadening in the trunk.

E) Smaller tires - swap them out with some of those really lame touring tires on oem steelies. Nothing says loving like 195/60x15 ... sleeper look, crappy traction, and good gas mileage. I would *HATE* to do this.

Anyways anyone else got any ideas/comments?

[LoungeLizard]

As far as the smaller wheels go, the smallest wheels we can fit are 16" because of the big brakes.

[nka]

Originally Posted by LoungeLizard

As far as the smaller wheels go, the smallest wheels we can fit are 16" because of the big brakes.

true, and smaller tire will make the rpm higher, so more gas millage! You just need smaller ou light wheels.

For the boost, you can buy a manual boost controler! But i'm not sure you will save gas with that trick!

[garland]

A manual boost controller for supercharged applications? Also, the rolling diameter of the tire is what's important, so I would just pick a taller tire. That in turn would lengthen the gear ratios and further improve it. Good point on the brakes though, I completely forgot about the massive size of our rotors :-/

[new2boost]

It's been said on this site before but if you are that worried about gas mileage then you shouldn't be driving a redline.

[mailmars]

Originally Posted by new2boost

It's been said on this site before but if you are that worried about gas mileage then you shouldn't be driving a redline.

Now thats the truth... One thing that I have done is use the boost gauge as a driving limiter on the work commute. The game is to keep the needle at 0 or below. Stop and go traffic which also includes one of the many 8 lane parking lots that some foolish person called freeways..... About 25mpg....


Mark

[pclear9061]

see i love how a s/c can get as good and better mpg than my 96 gs eclipse. thats non-turbo for those who dont know. and that got like 26 and in this im getting ~26-30 and im always running 91 even tho sometimes cannot afford it it worth not giving the engine what it needs.

[Sp00ner]

Eaton lists the parasitic loss on the M62, at 60mph, to be .3hp... the bypass was created after 'clutch style' bypasses were having durability issues.

Get a boost gauge, if you don't have one, and stay at 0 or below.

The worst part of mileage in this car, is the stop and go stuff. On the regular highway, I get almost 30mpg, yes I know it's supposed to be 28, but that's what I got last time. Around town, I get 19-20mpg.

[CarNut]

You would not necessarily need to go taller tires to increase mileage. Performance tires are not always good for mileage. For example, my truck came with 245/75 16" off-road Firestones. They have no wet traction and I couldn't stand the noise so I got some 265/70 17" Pirelli Scorpions for summer. These are HR speed rated with 520 A A gov't quality rating. Nice tires, but even adjusting for the slightly larger diameter I drop from 15 to 14 mpg when I switch over. It seems like I need a little more throttle as well. It would be interesting to try a set of stock 16" L-series wheels/tires on the RL and see what the mileage is.

[GaRsNoW]

Not to be a dick or anything, but if your that uptight about gas milage..i think this is the wrong car for you. The car is begging to be opened up. Again, no offence or anything, but a 4cyl s/c isnt askin to be granny shifted a hole tank.