mitchfried

One of the side effects of installing the Injen air intake to my old Mazda6 was an increase in miles per gallon from about 16.5 to 18.5. Although it looks like a large increase in power may not be available in the RX-8 with an intake, how about an improvement in fuel consumption? Any K&N users see an improvement in MPG? How about a decrease ?

Jaguar_MBA

Hi, one fellow installed a drop in high flow filter, not sure if it was a green or an aFe from Racing Beat. He claimed an increase of 3 mpg.....which is very very good.

Another fellow claimed a 1.5 mpg increase due to premixing two stroke oil in with his fuel

Also I believe that an aluminum underdrive pulley and light weight flywheel would also increase mpg........if you can control yourself and not redline it.

MELRX8

All things being equal I would think any improvement to engine efficiency would improve mileage. I have the aFe drop-in filter and realized a difference of 2.5 - 3 mpg on the highway.

JeRKy 8 Owner

Go and find an old lady w/amnesia at a nursinghome and convince her that shes your valet driver. That should be one hell of a gas mileage modification.

310Guy

Yet again, another pointless post by you... what a shocker...

JeRKy 8 Owner

Pardon me --I was unaware that the content ofmy posts meant somuch to you. Ill keep that in mind next time sweety :p

Xyntax

I've got a CZ map for MPG gains in the works. I'm still tweaking and logging results. It takes time coz I have to keep my driving style the same. So far, so good :D

ptiemann

Hm, if a mod improves mpg by 1 only.. it better be a cheap mod and easy to install.
It might not mean that much $$$

Jaguar_MBA

Not sure how this "paste-in" will look but any savings, even if only 1MPG will add up over 100,000 miles driven. My rough math says that a 3MPG savings with the aFe filter will save you $1,165 - $55 for the filter = ~$1,110. This is based on fuel being at $2/gallons. Savings are magnified if pump prices increases..... if $2.2/gallon then estimated savings over 100,000 miles would be $1,232. Plus then you need to factor in that you do not have to buy a new filter ever, just a recharge cleaning kit.


Miles
Between Cost per Input
$/Gal Avg Tank Fill Refills MPG tank Ratio Miles
BASE Before 2 11.876 259.5 21.85079151 $23.75 0.091529865 100000 $9,152.99
aFe After 2 11.876 297.37 25.03957561 $23.75 0.079873558 100000 $7,987.36
Savings $1,165.63

Xyntax

The MPG that people complain about has to do with the many visits they make to the gasoline station. I don't complain much about the numbers in $ currency, I complain about the frequent gas station visits.

Jaugar, you must be an Accountant huh? This is the 2nd post I've seen from you with numbers involved. Thanks for showing us something few of us didn't think about. I know Polak made the same statement long time ago, which lead me to buying the RX-8 anyway :D

Jaguar_MBA

Xyntax, close but I am not an accountant....but I do work in Finance.

A basic premise I have is that you truly understand an item when you can explain it with numbers.

Relentless

You're also not just paying for the mpg increase -- you're also getting a performance improvement.

Any improvement in the exhaust system would also help gas mileage.

JeRKy 8 Owner

I wonder ifthe green filter helps mileage as much asthe aFe filter or iftheyre about the same.

Xyntax

^ I'm wondering the same thing too. Anyone have a good experience with those aftermarket drop-in filters? Any bad ones too?

Snoochie

I just bought the green one and I always keep track of my mileage so I'll post the exact increase in my car, which doesn't mean it'll be the same for everyone else but a good rough idea.

Vaillant

I would think that if your car is one of the ones running rich, the Canzoomer 1.1 will help with mileage (plus give you some power). One of these days I'll be getting one and I'll let everyone know (I've been tracking every tank of gas to this point).

Also, so far, it looks like lower octane gas might be helping. It's hard to tell because I had a long trip in the mix, but after 5 or 6 more tanks I should have a good idea.

~ Matt

zevans

I think my K&N has improved mileage slightly. This makes sense since everything seems a bit freer in the mid-range now, and the mid-range is where you drive for good mileage.

Best mod you can do is improve your driving style!

Snoochie

^ True dat. I usually get about 17/18 mpg and then i tried really hard to run it easy and got 23. Meh I like fun more than money.