Balancing Act

RSX Fuel economy update

Here’s a short follow-up on the fuel economy of the 2005-2006 RSX Type-S. I have beaten my old record over July 4th weekend with a whopping 383 miles to the tank.

382.7 miles on the tank, and the empty fuel indicator hasn’t lit yet!

As some of you who have been following my previous entries detailing the trial runs for the best fuel efficiency on my 2005 Acura RSX Type S would remember: any aftermarket cold air intake / free flowing air filter diminishes the fuel efficiency of the RSX by as much as 12.5% or more. To put it in perspective, the maximum estimated miles I’ve gotten off a full tank with an Injen cold air intake installed was 460-470 miles, ± 5.0 miles. This number came from purely highway driving with no load, one person and at a constant 75 miles per hour while driving in cold and rainy conditions for the most part (from Crescent City to Los Angeles).

I’ve recently took a trip up north to Monterey, California for July 4th weekend with my girlfriend and with moderate luggage load. With two passengers and the load on board while driving at an average speed of 70 miles per hour (for the entirety of the trip), I was able to bank 382.7 miles. The drive from Monterey back to Los Angeles was about 340 miles taking the pacific coast highway 1 down to San Luis Obispo, then back on the 101-South. I was able to make it back to Los Angeles on a full tank of gas AND make a roundtrip to work and back home the following Tuesday without triggering the low fuel indicator! I’m pretty confident that I could drive until the trip meter hits 400 miles before the low fuel indicator actually lights up. Of course I had to contend with bumper to bumper traffic in Los Angeles on Tuesday, so that ultimately affected the MPG rating at the latter part of the trial. Two years ago, I made the same trip, same setup, but with the cold air intake on and I didn’t even make it past Calabasas without having to stop over and refuel.

This sums up another point. Stock for stock (minus Acura’s A-Spec ground effects kit and a high wing spoiler), highway driving while transporting moderate luggage and two passengers yielded 382.7 miles on the tank. I suspect that I could even hit the 500 miles mark (or at least very, very close) if I lowered my speed down to 65 miles per hour while driving solo with no load to carry. The Acura RSX Type-S is an incredibly fuel efficient vehicle compared to other cars in its class. We’re talking 33.22 to potentially 43.48 miles per gallon. No hypermiling techniques employed. Wow.

2 thoughts on “RSX Fuel economy update

  1. Steve Khou

    460-470 miles is about right, strictly 100% hwy driving at cruising speed. I recall refueling at 435 miles at 3 notches above the Empty mark and before low fuel indicator light was lit in Sebastopol, CA driving from Crescent City, CA to Los Angeles with the CAI on. That's how I estimate at 460-475 before the empty fuel indicator will light up. I did mean 500 miles, not MPG – lol, big typo right there.

    On a normal day-to-day commute, city / highway combined from school to work and back with moderate stop-and-go traffic, the CAI negatively effects MPG. The CAI definitely amplifies poor MPG effects of rush hour/bumper to bumper traffic. I haven't had the chance to replicate another long 750+ miles Crescent City to LA road trip with the stock air box, and I've sold the RSX a week ago.

  2. Daniel Lin

    A couple things in here don't at up.
    First paragraph you said 460-470 miles, did you mean 360-370? — It doesn't make sense because you said having aftermarket intakes decreases the efficiency.

    Paragraph 3 you said 500 MPG… I think you meant to say miles.

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