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I'm from the show me state. I find it difficult to believe that it can get over 30 on mostly flat roads. My best was 26.1 with 93 octane and fairly flat roads. But then again, I can't drive 55!
 

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gizmo2004 said:
That is INCREDIBLE mileage! Do you keep a raw egg under the gas pedal?

Is this from the DIC or actually writing down the accumulated miles from the odometer, subtracting beginning mileage from ending mileage, and dividing by the gallons actually put into the tank?

Not doubting you, of course. But WOW!

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sorry for the delay... computer renovations.
egg under the gas pedal.... that is a good description. also letting the speed drop off a bit going uphill. keep in mind also that this was highway only mileage on a motor already at operating temperature as reported by the DIC. not a scientific test, but if the DIC is accurate, it is impressive mileage for a car designed to be fun first.
 

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I drive 50 miles everyday @ 65-70mph. My DIC says my average speed is 34 and the gas mileage is 21. :willy:
My pen&paper method said 25 mpg.
 

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Gas mileage

Currently have 800+/- mi. on my Sol, with the longest "trip" a 6 mi. jaunt between two bars (or taverns, if you prefer). Hey, I'm retired and don't have anything else to do & it keeps me out of my wife's hair. At any rate, the DIC shows 20.6 right now. Don't see much value in keeping mileage until it hits 1000 mi. Starting to keep record next week.
 

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2late4-1000 said:
Currently have 800+/- mi. on my Sol, with the longest "trip" a 6 mi. jaunt between two bars (or taverns, if you prefer). Hey, I'm retired and don't have anything else to do & it keeps me out of my wife's hair. At any rate, the DIC shows 20.6 right now. Don't see much value in keeping mileage until it hits 1000 mi. Starting to keep record next week.
Just to repeat myself, I suggest establishing a free login at the fueleconomy.gov website. It's a handy way to keep track of your mileage. Here's an easy link:

http://www.fueleconomy.gov/mpg/MPG.do

Plus, the system gives the average mileage for all vehicles of the same make. There are now 9 Solsti providing data.

.
 

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solli4me said:
I drive 50 miles everyday @ 65-70mph. My DIC says my average speed is 34 and the gas mileage is 21. :willy:
My pen&paper method said 25 mpg.
Your average speed is always going to show a lot less than most people expect ... it seems there's always down time where you have the car started but aren't moving or slow down significantly. Also, unless you've reset your gas mileage on the DIC, it's probably reporting lifetime gas mileage. If you want to actually compare your figures to the DIC, reset the gas mileage figure as soon as you fill up one time and then get the figure at the next fillup to see if it matches your calculation for that particular tank. (Unless you've already done that and it still doesn't match.)
 

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Aftewr 6 months of driving my new-to-me 2006 Solstice I have become obsessed with gas mileage calculating. The last few were done the classic way: miles calculated per (Imperial) gallon. I am consistently getting 27 - 29 mpg mixed (mostly) city and some highway driving. I have taken to getting into the higher gears efficiently and cruising at 1500 rpm. I know that is lower rpms but I feel no engine lugging. I learned this driving attitude from a 'pro' driver's website, where he also criticizes using the transmission to slow the car down. His approach is to anticipate traffic movement etc, and plan ahead to slow down to 1200 rpm before shifting to neutral for the upcoming stops. Downshift rarely. He argues brakes are way cheaper than transmission repairs. And I feel the brakes are not being 'abused' either with this method. My QUESTION. Is this okay for this type of engine and transmission, etc? I have owned much older Japanese sporty cars where I was 'told' that they 'need' higher cruising rpms. btw the DIC readout is really inaccurate regardless of my driving trips.
 

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I don't like to load the engine much below 2000 RPM.

Have you reset your fuel economy reading?

You mentioned resetting the trip odometers but didn't say anything about the economy reading. I have found mine to be quite accurate on average, certainly within 2-3 MPG. I haven't actually compared it to the calculated value recently, but will take this opportunity to do so.
 

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Update: I pulled out my log books and did some calculations for all of the driving I have done in both cars since December 2018.

RL: 8,057 Miles, 322.3 US Gallons, 268.4 Imperial. Calculated average = 25.0, DIC = 24.8. Imperial average = 30.0. US MPG per tank ranges from 21.1 to 28.2.
NA: 2,067 Miles, 89.8 US Gallons, 74.8 Imperial. Calculated average = 23.0, DIC = 21.4. Imperial average = 27.6. US MPG per tank ranges from 21.3 to 24.1.

The NA was only driven in mixed town and country driving during that time, but the RL has also taken several highway trips that would skew the economy upward somewhat.
I put regular grade in the NA and mid-grade in the RL, and the average fuel cost for that period was US$0.10 for the NA and US$0.11 for the RL.

The range of calculated mileage shows the danger of using a single tankful to make judgements. Different pumps at different stations shut off in different ways, and some surfaces aren't quite level. It doesn't take much difference in either to make a significant difference in your calculation when your fill volume is only 10-12 gallons.
 

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i have only a little bit over 3,000 miles on my 09 2.4 NA coupe with the GMPP air intake assembly. no other mods

i keep a spread sheet for all my vehicles and i have averaged 20.37mpg over 3087 miles for the Solstice. i have no clue what the DIC says

Bill
 

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Excellent data, John.

Do you drive both cars the same way - for instance you aren't a little heavier footed on the NA trying to get it to go more like the turbo car? If not, that is a great comparison of the difference the smaller displacement makes.
 

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Excellent data, John.

Do you drive both cars the same way - for instance you aren't a little heavier footed on the NA trying to get it to go more like the turbo car? If not, that is a great comparison of the difference the smaller displacement makes.
To the limit of my ability to really tell they are driven the same way, but there is no way to know for sure. I do push the NA a little harder during acceleration onto highways, but not as hard in general driving partly because it has a louder exhaust. I am more likely to accelerate the RL at random times simply because I can.

The close match in operating costs is consistent with drives that I have done in the NA with RL and GXP drivers. They got better mileage, but I used cheaper fuel, so the cost was comparable. In those days the price step between grades was $0.20 so the NA came out on the short end, but now it is $0.40 to $0.60, so the NA is less expensive by a similar margin.

On a further note, my RL is not tuned. The GMPP tune (I don't know about the others) can improve fuel economy even as it increases power.
 

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You should look into Low Speed Pre Ignition
re: Low Speed pre-ignition. Interesting topic. Thanks. AllI could find is that it is a topic without definitive conclusions, but that a turbo engine can really suffer from it. Some sites suggest that as long as you are not trying to exert power (instead of down-shifting) then it is quite alright to cruise at 'low' rpms. I would like to find out just what is generally acceptable for my 2006 basic 4 cylinder v-tech engine.
 

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re: Low Speed pre-ignition. Interesting topic. Thanks. AllI could find is that it is a topic without definitive conclusions, but that a turbo engine can really suffer from it. Some sites suggest that as long as you are not trying to exert power (instead of down-shifting) then it is quite alright to cruise at 'low' rpms. I would like to find out just what is generally acceptable for my 2006 basic 4 cylinder v-tech engine.
If you are serious about this you should monitor the engine to see what is going on. You can buy a really inexpensive OBD adapter, install the free Torque app on your phone, and actually watch the engine react to your driving. There is really no substitute for knowledge.
 
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