Eco modding an RSX

[pete c]

I've been considering getting a new car for work.

My requirements are......

Good mpg, hatchback, pleasant to be in for long stretches, reliable, fun

I have been looking an insights, G1 and 2. Both have mileage covered, but my concern is they are both very light and I might eventually hate being in the thing for upwards of 8 to 10 hours a day.

I recently have been looking at RSXes. Yeah, the mileage ain't anything to write home about as they are rather short geared, but I was wondering if with a few mods, grill block, taller tires, WAI, would it be possible to at least get into the mid 30s? I also read that the K motor is happy with lean burn.

Does anyone know if it can have a higher top gear installed? This engine is known to have pretty good low/mid range torque. Seems kind of silly to have it spinning 3k at 65 mph.

I would like to hear from anyone that has one. Oh and it must be a 5-6 speed.

[spdfrk]

Wife has an '05 TSX auto with the 5 speed. Put a small lip spoiler on the trunk, grille block with inserts, Nokian low rolling resistance tires, and some low viscosity fluids (Amsoil in the engine with ws2 and NMF, Amsoil low viscosity ATF with a couple ounces NMF, Honda power steering fluid flushed, Amsoil HD antifreeze and then topped up with blue Honda stuff so it still looks blue). The coolant temps dropped drastically after the HD antifreeze. So much so I replaced the thermostat thinking it was stuck open. Indexed the NGK iridium spark plugs. Drag coefficient matches a 1st gen Prius at .27 Cd. Cheap to run and very reliable. Just replaced the struts and springs all around and it handles like it's on rails.

It does about 8.5L/100km city and can do 6L/100km easily on the highway.

[pete c]

Imagine a taller 5th gear and lean burn. It might approach 50mpg.

[Shortie771]

And you can input the numbers into HERE and also change the tire sizes to see the effect on speeds as (with a little elementary math) calculate the differences as a percentage to figure out what kind of mpg increase you could potentially get.

Edit: Not sure if you could do a full tranny swap (might now bolt up) with an 03-07 Accord, but I've read that all of the internals are interchangeable. So if nothing else you could either swap the internals or do a 5th gear swap. I realise it's a lot of work though.

[ksa8907]

As a side note, lexus makes a cousin to the prius. I have no idea about creature comfort or space but the mileage is a bit lower.

[Ecky]

What does does being light have to do with how much you like being in them? Just curious.

For what it's worth, the G2 Insight weighs within maybe 25lbs of what an RSX weighs.

[Daschicken]

Originally Posted by pete c

I've been considering getting a new car for work.
I have been looking an insights, G1 and 2. Both have mileage covered, but my concern is they are both very light and I might eventually hate being in the thing for upwards of 8 to 10 hours a day.

Are you considering the base, or type-s? Both? G2 insight is not light. What is the concern about being light? I have heard that G1 has pretty loud road noise, but nothing a good amount of sound deadening couldn't fix.

A while back I compared the profile of the G1 insight to the RSX, it was EXTREMELY close. I just couldn't understand how the drag coefficient on the RSX was at .32, while the insight had .25. I think the major differences contributing to the RSX's higher number are: No undertray, non-aero wheels, no rear wheel skirt, no boattailing the SIDES of the rear of the car, fenders not radiused, wider tires, bigger radiator, etc.

Originally Posted by pete c

I recently have been looking at RSXes. Yeah, the mileage ain't anything to write home about as they are rather short geared, but I was wondering if with a few mods, grill block, taller tires, WAI, would it be possible to at least get into the mid 30s? I also read that the K motor is happy with lean burn.

If you use the ecodriving tips above, you should have absolutely no problem hitting mid 30's stock. Also...


No. Seriously. You should be aspiring to MUCH higher goals than mid 30's if you get a base RSX. I would suggest grill block, undertray, rear wheel spats(if it doesn't have already), engine block heater (about $50-60 OEM). I just recently got an engine block heater for my car, makes me wonder why I didn't get it sooner. It doesn't have to be cold for you to benefit from it, I turned mine on when it was 75 degrees F outside. Came to the car 2.5 hours later with a coolant temp of 125F.

Originally Posted by pete c

Does anyone know if it can have a higher top gear installed? This engine is known to have pretty good low/mid range torque. Seems kind of silly to have it spinning 3k at 65 mph.

Yes, you can swap in the 5th gear from an accord, or other cars listed above. The 8th gen (2008-2012) accord in the list above has the tallest 5th gear. The 2002-2004 RSX Type-S has a taller final drive than the 2005-2006 Type-S. I don't know who told you that engine has good low end torque, but they are lying. My K24 accord, which is torquier than the K20 in the RSX did not have good low end torque. Mid range torque? Yes, lots of it, but not much low end torque. Yes, it would be able to pull a taller top gear with no problem at all.

Originally Posted by pete c

I would like to hear from anyone that has one. Oh and it must be a 5-6 speed.

The base is a 5 speed, type-s is 6 speed.

Originally Posted by pete c

Imagine a taller 5th gear and lean burn. It might approach 50mpg.

My V6 Accord is approaching 50 MPG, of course it could approach 50 MPG! It could probably do it out of the box with the right commute and driver.

[pete c]

Originally Posted by Ecky

What does does being light have to do with how much you like being in them? Just curious.

For what it's worth, the G2 Insight weighs within maybe 25lbs of what an RSX weighs.

The difference is that a light car bounces around on rough roads. While reading reviews of the RSX, I noticed many people describing it as solid or substantial, moreso than say a civic. And that it would be a comfy car for long hauls.

I am sure even a G1 could be made more comfy with added sound deadening and maybe a better seat.

[Ecky]

The G1 doesn't sound-deaden very well for whatever reason. I suspect it has to do with the suspension being all aluminum, or its design, or something. However, mine definitely rides better when I have a bunch of weight in it.