Cruise Control & Fuel Economy

[IBCoupe]

Alright, guys, bear with me. Installed the new intake on Friday, and drove pretty aggressively to play with it. This isn't one of those threads. Does anybody with a CVT pay an absurd amount of attention to their fuel economy, like me?

I found, Saturday afternoon and Sunday night, when I did a lot of highway driving, that the car thought I had a longer range in manual mode, cruising in the simulated 6th gear at 75 to 80 mph than I did in Drive with cruise control set to about 63 mph.

For example, I speed in manual mode, and the computer telling me the estimated range combined with the mileage on the trip odo tells me that I'm aiming for about 480 miles that tank. In cruise at 63, it drops down to about 445. After driving around Long Island for a day and a half, range was lower, but the same disparity was apparent. High speed in manual mode: 425 mi. Moderate speed in cruise: 412 mi.

I-95 in CT is relatively flat, so I'm pretty sure I can rule out topography in the different stretches of road as a factor.

So what gives? Has anybody else run into this? Is it the new intake? Has the ECU not properly adjusted yet? Have I just overestimated the efficiency if cruise control this whole time?

[LongIslandAC2010]

No idea but now I'm very curious to find out if "manual" mode is in some weird way more fuel efficient than cruise and regular automatic.

[kscott]

I'd suggest using the average MPG that you've already driven, and reset it when you change driving styles. Don't use the estimated miles-until-empty for this kind of comparison, since it involves the amount of gas it thinks is in the tank, another variable in the calculation, which probably isn't all that accurate.

[masterbeatty]

IDK i drove across the country and got better MPG in auto and with premium.

[IBCoupe]

I'd suggest using the average MPG that you've already driven, and reset it when you change driving styles. Don't use the estimated miles-until-empty for this kind of comparison, since it involves the amount of gas it thinks is in the tank, another variable in the calculation, which probably isn't all that accurate.

I'll give that a shot the next time I fill up. I'll do one tank in either driving style, and report my results in less than two weeks.

[PHENOMenalVinyl]

Alright, guys, bear with me. Installed the new intake on Friday, and drove pretty aggressively to play with it. This isn't one of those threads. Does anybody with a CVT pay an absurd amount of attention to their fuel economy, like me?

I found, Saturday afternoon and Sunday night, when I did a lot of highway driving, that the car thought I had a longer range in manual mode, cruising in the simulated 6th gear at 75 to 80 mph than I did in Drive with cruise control set to about 63 mph.

For example, I speed in manual mode, and the computer telling me the estimated range combined with the mileage on the trip odo tells me that I'm aiming for about 480 miles that tank. In cruise at 63, it drops down to about 445. After driving around Long Island for a day and a half, range was lower, but the same disparity was apparent. High speed in manual mode: 425 mi. Moderate speed in cruise: 412 mi.

I-95 in CT is relatively flat, so I'm pretty sure I can rule out topography in the different stretches of road as a factor.

So what gives? Has anybody else run into this? Is it the new intake? Has the ECU not properly adjusted yet? Have I just overestimated the efficiency if cruise control this whole time?

You have your better gas mileage in a high gear why is that odd. Your car might have been sitting at 63 in "5th" and you don't even know it. I discovered the best MPH for MPG is 67mph at 35.5mpg for me atleast but i get horrible mileage. I don't know if that made any sense but that's my idea on it

[IBCoupe]

The CVT shouldn't be doing that, Matt. The point of it is that it's seeking the most efficient "gear," without being restricted by physical gears.

Last night, to and from school, I left it in drive, cruise control on, but varied the speed based on speed limits. When I got back, these were my results.

MPG: 27.7
MPH: 54.2

I'll see what I get out of manual mode.