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Discussion Starter #1
Is it possible to swap out for a taller 6th gear [ratio]?

I have been researching online that it is somewhat possible to help improve gas mileage to swap a taller final gear ratio into your drivetrain, but what I am looking for is specifically highway mileage to improve. I have a 120 mile round trip to work every day, so you can see that better gas mileage would definitely help here.

I understand that the way fuel efficiency works with the drive train and gear ratios is that you must take into account the load on the car as well as air flow, but given that we all drive an RSX, our load capacity is fairly low (mainly just passengers and whatever is in the boot).

(please no "get a different car" quotes)
 

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Honda, unfortunately, sabotages the gas mileage of their manual gearboxes in order to make the fuel economy of their auto transmissions look better. The auto is a higher-profit item for them. My base auto only turns 2400rpm at 65mph and I get 42mpg at that speed, but then the base has a different torque curve than the type s. That gives you an idea of what's possible. The base auto has a top gear ratio of .571 compared to .738 for the type s and base manuals. Final drive for the auto is 4.562 vs 4.389 for the manuals.

Bigger wheels would help somewhat, but those come with their own set of drawbacks.
 

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Discussion Starter #4
Jay:
I know bigger wheels can add more weight unless they are very lightweight race wheels, but what drawbacks come with them.

Revilingfool: I have been told of the tsx 6th, but I was told it only helps 1-2mpg at best. Also I dont know what else is required for this upgrade (bearings, shafts, etc...)

Is it possible to swap to the TSX 6th gear as well as alter the final drive to get a lil extra?
 

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It messes up your speedometer and odometer, increases the turning radius, presents clearance problems when you turn (depending on how big you go), raises center of gravity and might present suspension geometry problems.

Don't know about what other transmissions or gears might work, but then you're looking at major surgery for two transmissions.
 

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Jay:

Revilingfool: I have been told of the tsx 6th, but I was told it only helps 1-2mpg at best. Also I dont know what else is required for this upgrade (bearings, shafts, etc...)

Is it possible to swap to the TSX 6th gear as well as alter the final drive to get a lil extra?
you should be looking into another car if you want mpg. remember the diesel jetta documentary thing where it was around 90mpg
 

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Discussion Starter #9
you should be looking into another car if you want mpg. remember the diesel jetta documentary thing where it was around 90mpg

I knew that comment would come up sometime sooner or later. Payments are still being made on the car and I do not want to trade it in, just to put more bills on myself from something else.

BACK ON TOPIC THOUGH. I have looked into combining the TSX 6th with a 4.3 Final Drive which may help with mileage but may lower power a little bit. All in time and research will I make my decision, but I also first need to calculate if it is a worthy investment, and how long it would take for the investment to pay at least itself off.
 

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Well, figure if it saves 1-2 mpg, you'll save about $1.50 a tank. Thats 150-200 fill ups for the savings to equal just the cost of the gear. Add in other expenses like seals, gaskets, fluids, and your own time, and I'd say a decent estimate is 400 fill-ups before you really break even with the supplies and time you put into it. If you don't care about your personal time, still 250-300 fill-ups. If you use a tank a week, thats over 5 years, almost 6.
 
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