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Discussion Starter · #1 ·
I've had my I-4 Terrain FWD for 2 mos. now and 3K miles. Back and forth to work at 60-70MPH on the interstate yields excellent mileage--29-33 MPG. Around town for extended periods has average about 23-25 MPG. But if go for a longer ride, like yesterday for example, interstate only and at 75-80 MPH, the I4 only managed 24.7 MPG for a 340 mile round trip. Flat, little wind, and not much traffic to deal with. Temps in the lower 80's. The mileage drops like a rock when the speedo gets above 70MPH---at least for me--and I'm trying to keep a constant speed. The instant MPG on DIC shows pretty much what I get on trip MPG readout. Either I got to get a lighter foot or forget what mileage I'm getting.
 

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I have the same experience. MPG really takes a hit over 65. I'm sure MPG ratings are done at 55 and with the smallish engine, going faster taxes the motor and drops efficiency.
 

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We've been getting the best MPG going 68-71. Wife took a trip and averaged about 78 and she got 25.6 per the DIC.
 

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Discussion Starter · #4 ·
I guess the best answer is to stay in the sweet spot if you want the MPG and put your foot down if you don't care. While I've always had that attitude, it just seems the drop off in MPG is pretty extreme in the I-4's. I got better MPG at 75-80 in my 07 Vue with a 3.5 V-6. But, then again, I never saw 31-34 at 65 either!!!
 

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A little off-topic, but why is the DIC average MPG always about 1-2 MPG higher than my calculated MPG. I could see it being high and then low, but average over a few fill-ups being accurate, but mine is consistently high over 3000 miles. Doesn't it use a flow-meter? I know - some say the pumps are lying, but I find that hard to believe - although I did put 19.6 gallons of gas into my 19.5 gallon tank in North Carolina. I attributed that to squeezing it into the filler neck. Make sense ?

Any thoughts?
 

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RIT333 said:
A little off-topic, but why is the DIC average MPG always about 1-2 MPG higher than my calculated MPG. I could see it being high and then low, but average over a few fill-ups being accurate, but mine is consistently high over 3000 miles. Doesn't it use a flow-meter? I know - some say the pumps are lying, but I find that hard to believe - although I did put 19.6 gallons of gas into my 19.5 gallon tank in North Carolina. I attributed that to squeezing it into the filler neck. Make sense ?

Any thoughts?
I'm sure all of the gauges and measuring instrumentation have a certain error tolerance.
 

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Maybe DIC ignores idle gas usage. Maybe only calculates gas used while in drive or moving. Just a thought.

Can someone test this theory?
 

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I have almost 1500 miles on my I4 Terrain and have averaged 25-26 every tankful...Highest speed i go is maybe 60..mostly long stretches hardly any interstate driving..I love the SUV..and really like the I4...
 

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My DIC is pretty close - I4 getting around 28 City / Suburban use. Unusual thing for me is I get 28-29 on the Highway also. Still new so we will see this summer with several trips on the docket.
 

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So far I'm only getting 17 mpg (SLT2 6cyl) Filled up last night...295 miles and 18 gal of gas. All the warnings were going ....the gage showed empty, the light was on and the driver info screen said "LOW FUEL". I thought the tank was around 20 something gallons. What is the longest milage anyone has had from a full tank of gas with the V6??????
Is there a loud buzzer when it gets down to 1 gal? LOL

One thing I did discover last night. There is a little hook on the gas door to hang the gas cap. Never noticed that before and was a little disappointed that there was nothing to keep the cap from hitting the side of the car. I'm happy now. ;D
 

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It seems the ECU's is tuned for maximum fuel efficiency under 70mph. I have tested cruise control on various speeds on the highway and under 70mph is the best 28-35 MPG range, I only have 600+ miles on it right now. Wonder if the mileage gets better with more miles on it like some other vehicles.
City driving is pretty good with cruise on also, only problem with that is it's only short cruising till the next light lol.
 

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SnowItch, AWD
99% light suburban traffic
 

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RIT333 said:
A little off-topic, but why is the DIC average MPG always about 1-2 MPG higher than my calculated MPG. I could see it being high and then low, but average over a few fill-ups being accurate, but mine is consistently high over 3000 miles. Doesn't it use a flow-meter? I know - some say the pumps are lying, but I find that hard to believe - although I did put 19.6 gallons of gas into my 19.5 gallon tank in North Carolina. I attributed that to squeezing it into the filler neck. Make sense ?

Any thoughts?
Don't forget, gasoline does evaporate extremely easy. My suggestion is to keep you tank as full as possible. With less expansion room in the tank, the likely hood of loosing gas to evaporation is less. I try to make a rule of getting gas at 50% full.

Does that account for a full 1 or 2 MPG? I don't think so, but it does contribute at least a little.
 

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Time-out - I thought the EPA won't allow evaporation of all those noxious fumes, hence the sealed gas cap, and check engine light when you don't put on the gas cap. I don't buy that as a reason. Possibly heat/cold expansion of the liquid (gasoline), but I doubt if that is measurable.
 

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Produce a report done by a trusted non-profit 3rd party and I'll believe it. So far, there have been no trusted 3rd parties. A lot of 3rd parties yes, but none of them are trusted 3rd party non-profit. All studies produced have been paid for in one way or another by the synthetic oil companies or vested interests. So believe what you will. And remember P.T. Barnum "There's a sucker born every minute"...
 

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Narg said:
Produce a report done by a trusted non-profit 3rd party and I'll believe it. So far, there have been no trusted 3rd parties. A lot of 3rd parties yes, but none of them are trusted 3rd party non-profit. All studies produced have been paid for in one way or another by the synthetic oil companies or vested interests. So believe what you will. And remember P.T. Barnum "There's a sucker born every minute"...
You can increase MPG with fluids...but its certainly not the "oil" that does it. Its going to a "lighter" oil that reduce friction. Less friction, slight increase in MPG. I use a moly additive (mos2) in my engines, it cost just about nothing...and on the company car (which I drive on average 4k a month) I've seen an increase in just under 2mpg since adding (ran for 6months without and now doing it every oil change...the results speak for themselves because I have a gas card that tracks mileage and tank average MPG which I get monthly)

The car runs a Kendall Blended oil 5w30.

Reprogramming the ECM is the best way to increase MPG. Our engines can easily run much leaner while on light loads then regular fuel injection. The problem is catalytic converters are not up to par, they are only effective at removing certain emissions @ certain AF's. When running our ECM shows a commanded 14.7:1, but its constantly floating richer, leaner because of emissions. The cat removes hydrocarbons @ lean AF's and Nox @ richer AF's. For some reason the US consideres Nox a harmful emission, which makes lean burn illegal in the US, but its what DI is designed to take advantage of.

I'm talking w/ the tuner of my last car (trifecta tuning)N and they are soon to add support for the our ECM,

For the record, your vehicle uses a new Delphi engine controller called the E39, not the Bosch controller like the LLT/LNF (E69). I actually just added support for it in EZ Flash last weekend, and we have a customer in New Jersey who is going to test the tunability of it very soon – he wants to slap a turbo on his 2010 Cadillac SRX. Lol/
 

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I also have read a couple tests done by third parties. One was called "The Oil Bible" and the others I can't remember because I read them and then closed the website......not thinking that someone in the future would say there is no such thing. I suppose when SnowItch posts that report someone will say "I don't trust that person" So it's a no win situation.
 

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GARYD said:
I also have read a couple tests done by third parties. One was called "The Oil Bible" and the others I can't remember because I read them and then closed the website......not thinking that someone in the future would say there is no such thing. I suppose when SnowItch posts that report someone will say "I don't trust that person" So it's a no win situation.
I'll help both of you here

Remember what I stated and read these links lmao

http://www.dailyfueleconomytip.com/uncategorized/will-switching-to-synthetic-oil-give-you-better-gas-mileage/

Today’s tip is a very subtle way for you to help increase your car’s gas mileage and fuel efficiency, will more than likely help increase the life of your vehicle, and, over time, will help you save some money.

Switch from conventional motor oil to synthetic oil.

The reason synthetic oil will probably help you achieve greater gas mileage is due to the fact it tends to lubricate your car’s engine better than conventional motor oil. Because of the better lubrication, there tends to be less friction within the engine, which causes the engine to run more efficiently, helping you achieve greater gas mileage.
19.Are there any gas mileage advantages to using synthetic oil?

Absolutely. Synthetic oils use higher quality friction modifiers to make the oil more slippery and stronger than conventional oils. This allows the engine to run easier and smoother, increasing gas mileage
What do they all say is the cause...FRICTION REDUCTION
 
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