CVT sweet spot at 68mph?

[ac7ss]

I have noticed a sweet spot at about 68mph, 2800rpm. MPG goes up to about 75 and I can keep speed.

Has anyone else noticed this spot? am I just imagining it? Any other sweet spots to know about?

[boogetyboogety]

I often manually-cruise at 70-75 mph and get mileage in the mid- to high-60s, a/c on Econ at 72°. With the Rostra cruise on, that can drop to the high-50s to low-60s. See #6:

What's your normal MPG at 55MPH?

Between 35-45 mph, normal city cruising, however, I can get substantially better mileage than other ranges. My ScanGage II frequently shows mileage in the 200+ mpg range, and the FCD display can max out for blocks on end without dropping speed on flat-to-slow-rolling Dallas streets. Here's what I recorded for a doubting Thomas last week on the way to his office:

[joecvt]

Originally Posted by ac7ss

I have noticed a sweet spot at about 68mph, 2800rpm. MPG goes up to about 75 and I can keep speed.

My best MPG spot is about 45MPH but there is probably a reason for the sweet spot that you noticed @2800 RPM. Even though you may not get the best mileage at that speed and RPM, the VTEC kicks in at 2700 RPM when under engine load. At a point just before VTEC under engine load, your MPG may be a bit lower until the secondary valve changes providing a bit more power allowing you to ease off the throttle just a bit but still continue with VTEC engaged.

JoeCVT = Just your average CVT owner

[ac7ss]

Originally Posted by joecvt

My best MPG spot is about 45MPH but there is probably a reason for the sweet spot that you noticed @2800 RPM. Even though you may not get the best mileage at that speed and RPM, the VTEC kicks in at 2700 RPM when under engine load. At a point just before VTEC under engine load, your MPG may be a bit lower until the secondary valve changes providing a bit more power allowing you to ease off the throttle just a bit but still continue with VTEC engaged.

JoeCVT = Just your average CVT owner

This spot is a transitory thing on my commute, as there is no real flat part for any considerable distance. (not to mention that part of it is highly patrolled.) But the VTEC was my suspicion as well.

[Kevin Dougherty]

I vote for 2,000 & 3,800 rpm in 5th gear, at least for the manual tranny.

[RobertSmalls]

Kevin, that BSFC plot is off a CVT, and may be tainted by IMA. And if you draw horsepower isolines, you find that cruising at 4000RPM puts you in the >280g/kWh range.

I really wish we had a useable BSFC plot, because it would answer these questions authoratively.

@ac7ss: Your mpg figure sounds quite a bit high for steady state cruising on flat land. Try using the FCD button to record mpg across a predictable part of your commute, and do it in the opposite direction on your way home. Record the mpg using different techniques, and you'll be able to tell what works.

[Mysticfyre]

Wow, I don't know how you're doing that well. I get about 47 when I'm at 75 and the A/C on 76.

My sweet spot is probably around 45 or so- I can get about 52.

[boogetyboogety]

Wow, I don't know how you're doing that well. I get about 47 when I'm at 75 and the A/C on 76.

My sweet spot is probably around 45 or so- I can get about 52.

I'm not sure to whom that was directed, but... make sure your tires are at 50#s, like mine; watch your fuel bars, keep them above 75 mpg; immediately release the accelerator when you see an upcoming stop, whether potential (e.g., a red light a block away that could change to green) or actual (a stop sign); don't pass other cars; drive away from a stop as though you had an egg under your foot that you didn't want to crush; "pulse and glide," accelerate slightly to just past your desired speed, then release your foot off the gas slightly once you reach your desired speed, and as you slow down, repeat; and whenever possible, follow traffic (I'm not advocating drafting like a race car, but even at slow speeds, following another car two-three-four car lengths back makes a difference. Two seconds back on the highway, please). Do those, and you may see a decrease in your consumption...

[joecvt]

Here is what I did yesterday with an average speed of 45MPH on a 25 mile round trip:



This was with some hilly areas and some stop and go....I wish I had a long flat area to try this on a hot summer day....Temp was about 85F and both windows fully open. OEM tires at 50 psi.

For a six mile stretch of road, I was at 99.4MPG I took this picture at the end of my trip while in AutoStop.

I think for a CVT, the best sweat spot range is at 40-45MPH.

JoeCVT = Just your average CVT owner

[red1dr]

Originally Posted by joecvt

For a six mile stretch of road, I was at 99.4MPG I took this picture at the end of my trip while in AutoStop.

Wow, those mpg's are amazing!!

Originally Posted by joecvt

I think for a CVT, the best sweat spot range is at 40-45MPH.

I think the same is true for the MT, or possibly even a touch slower.

Originally Posted by joecvt

JoeCVT = Just your average CVT owner

Maybe you need to change "average" to something else???