50mpg achievement!

[mpg_numbers_guy]

Originally Posted by 19bonestock88

Agreed, it’s not bad at all... I just thought I was gonna hit my goal...

We could do 600 mile road trips on flat country roads going 45 mph. That'll give us both 50+ mpg tanks.

[19bonestock88]

In theory a long flat trip with a 55mph speed limit and 70+ degree weather *SHOULD* yield a 50+mpg tank, provided all the P&G goes well... my commute has three big hills in it, which require going WOT for long periods and/or downshifting... car gets 19mpg instant in 5th, 13 in 4th, and like 9 in 3rd...

[mpg_numbers_guy]

Originally Posted by 19bonestock88

... my commute has three big hills in it, which require going WOT for long periods and/or downshifting... car gets 19mpg instant in 5th, 13 in 4th, and like 9 in 3rd...

For hills I generally maintain constant load usually at 50 mpg, and go until my mpg drops below 40 (or 45, depending on how high my trip average is at), then accelerate just enough so the engine doesn't downshift (being an automatic), then coast for a quarter of a mile with the speed I get. It actually seems to be helping MPG.

For example:

Trip MPG approaching hill: 50.0
Trip MPG halfway up hill with throttle at 50 mpg: 50.1
Trip MPG after accelerating up last half of the hill: 49.8
Trip MPG after coasting off the extra speed in neutral: 50.2

...and sometimes the gain is more significant. But that's with shorter, steeper hills.

Not sure if there's a more efficient way though. What do you generally do?

Most of my trips are 5-6 miles now, so it's going to be hard breaking that 50 MPG barrier.

[19bonestock88]

Two on the three hills in my commute are able to be taken in 5th gear, at between 80 and 100% throttle... the middle one, on my way to work, has a pretty impressive glide down the other side and for almost a mile further... if not for the curve at the bottom(that I can take at almost 65mph with bald tires on dry road) I could coast all the way to the third hill... the hill closest to home has hairpin curves near the bottom and partway up that can’t be taken much above 30mph, and the car struggles to hold it in 5th gear(~1200 RPM)... the issue with that particular hill is the low average speed it forces and that there’s no practical way to get back the energy it takes to climb it

[mpg_numbers_guy]

Originally Posted by 19bonestock88

Two on the three hills in my commute are able to be taken in 5th gear, at between 80 and 100% throttle... the middle one, on my way to work, has a pretty impressive glide down the other side and for almost a mile further... if not for the curve at the bottom(that I can take at almost 65mph with bald tires on dry road) I could coast all the way to the third hill... the hill closest to home has hairpin curves near the bottom and partway up that can’t be taken much above 30mph, and the car struggles to hold it in 5th gear(~1200 RPM)... the issue with that particular hill is the low average speed it forces and that there’s no practical way to get back the energy it takes to climb it

Makes sense.

Those WV hills are killers. I went through there last month on my way to a college visit, and the hills were crazy.

Added extra incentive for ecomodding for when I drive down there myself this fall.

[19bonestock88]

What part of WV did you drive through? What college ya going to?

[mpg_numbers_guy]

Originally Posted by 19bonestock88

What part of WV did you drive through? What college ya going to?

Pretty sure we took I-64 through WV. I'll be going to Liberty University in Virginia.

[19bonestock88]

Yeah there are some steep grades on I-64 lol... you passed through about 80mi south of me lol... I’m near US-33...

Best thing I found for the freeway, is to avoid the cruise control and be at the bottom of the hill faster than your target speed, slowly ramp up throttle until right before it kicks down, and hold that until you’ve either crested the hill or you drop slow enough to wanna accelerate... in my Malibu I cruised at 75-80 and would hold overdrive down to 62 before forcing the downshift... brought my highway mileage from about 35 indicated to around 38

[mpg_numbers_guy]

Originally Posted by 19bonestock88

Yeah there are some steep grades on I-64 lol... you passed through about 80mi south of me lol... I’m near US-33...

Lol, probably as close to seeing another of my kind as I'll ever be! Don't recall ever seeing an ecomodded car in all my years of life.

Originally Posted by 19bonestock88

Best thing I found for the freeway, is to avoid the cruise control and be at the bottom of the hill faster than your target speed, slowly ramp up throttle until right before it kicks down, and hold that until you’ve either crested the hill or you drop slow enough to wanna accelerate... in my Malibu I cruised at 75-80 and would hold overdrive down to 62 before forcing the downshift... brought my highway mileage from about 35 indicated to around 38

My dad drove, and of course with the speed limit of 70 he drove at 75 with the cruise control...which meant 3rd gear up the grades and killing the brakes on the downgrades lol.

[19bonestock88]

So, during my adventure of moving, I had to fill the car again... and despite about 15 miles of forced freeway use(state highway diverted due to bad house fire), I set a new personal best of 47.4mpg at the pump! I know it’s not 50 yet, but I’m trying guys... I figure that ambient temps are mostly to credit, as it was almost hot enough to overheat my car on the freeway... climbing the one hill, at 70mph, I seen coolant temps around 210F... not quite at the cooling fan kick on, but warmer than I’d like... on flat two lane roads in 90F weather, the car stays around 190-195F