Chevrolet Cruze Forums banner
1 - 20 of 31 Posts

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #1 ·
I filled up on the way home from work today....and finally managed to break 40MPG!
526 miles on 13.039 gallons = 40.34MPG (DIC estimated 42.6...about 6% high, which is typical...)

37.2 MPH average speed = ~57% city driving.

Not bad for an optioned out LTZ!

The only MPG "mod" on this one are Xtreme's advice on max'ing out the tire pressure to 44psi.
I don't use cruise control, and no A/C needed yet...highs are in the upper 70's/lower 80's here; lows are in the lower to upper 60's.
I am going to start logging the temperature at fill-up just to see what correlation the temperature has on MPG...should prove interesting.
Todays' temp at my fillup was a cool 67 degrees.

Hope to check my spark plug gap this weekend...will post findings later.
 

·
Premium Member
Joined
·
4,339 Posts
...yes, definitely, "Congratulations!" We'd be happy just to achieve the EPA numbers (dratz!).
 

·
Registered
Joined
·
36 Posts
I filled up on the way home from work today....and finally managed to break 40MPG!
526 miles on 13.039 gallons = 40.34MPG (DIC estimated 42.6...about 6% high, which is typical...)

37.2 MPH average speed = ~57% city driving.

Not bad for an optioned out LTZ!

The only MPG "mod" on this one are Xtreme's advice on max'ing out the tire pressure to 44psi.
I don't use cruise control, and no A/C needed yet...highs are in the upper 70's/lower 80's here; lows are in the lower to upper 60's.
I am going to start logging the temperature at fill-up just to see what correlation the temperature has on MPG...should prove interesting.
Todays' temp at my fillup was a cool 67 degrees.

Hope to check my spark plug gap this weekend...will post findings later.
kOOL
 

·
Premium Member
Joined
·
2,241 Posts
Woohoo! Congratz!

Sent from my DROID3
 

·
Registered
Joined
·
343 Posts
I filled up on the way home from work today....and finally managed to break 40MPG!
526 miles on 13.039 gallons = 40.34MPG (DIC estimated 42.6...about 6% high, which is typical...)

37.2 MPH average speed = ~57% city driving.

Not bad for an optioned out LTZ!

The only MPG "mod" on this one are Xtreme's advice on max'ing out the tire pressure to 44psi.
I don't use cruise control, and no A/C needed yet...highs are in the upper 70's/lower 80's here; lows are in the lower to upper 60's.
I am going to start logging the temperature at fill-up just to see what correlation the temperature has on MPG...should prove interesting.
Todays' temp at my fillup was a cool 67 degrees.

Hope to check my spark plug gap this weekend...will post findings later.

Congratulations! Ok I'll ask... what was your speed during the 43% highway driving? I've been putting it off since I'd have to feed the air pump, but I have to say the higher tire pressure seems to really make a huge difference.
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #7 ·
Congrats! It will be interesting to see if you can break that with the correct spark plug gaps.
I believe it's safe to say that mine will be out much like everyone else has already found...I find it HIGHLY unlikely that I would have the only Cruze on the highway gapped at the 0.033-0.037" spec!

Congratulations! Ok I'll ask... what was your speed during the 43% highway driving? I've been putting it off since I'd have to feed the air pump, but I have to say the higher tire pressure seems to really make a huge difference.
Here goes: (My ~28 mile commute to work....)
First ~6 miles from home to 4-lane speed limits do not exceed 40mph....neither to I; about half of these 6 miles are 35mph. There are 11 stoplights (Yes, I think Greensboro went on eBay and bought a boatload of them, and then decided to install them along my route!) I'd guess on average that I only have to stop at 3 of them...I only turn at 3 of the 11, the rest are drive-thru's.

The next 7 miles are 55mph limit, next 7 are 35/45, no stoplights, next 7 are 60mph interstate, last 2 are rural with one light to work.

In the 55/60 limits I do somewhere around 55-62mph.

Car rests on weekends!
 

·
Registered
Joined
·
343 Posts
Here goes: (My ~28 mile commute to work....)
First ~6 miles from home to 4-lane speed limits do not exceed 40mph....neither to I; about half of these 6 miles are 35mph. There are 11 stoplights (Yes, I think Greensboro went on eBay and bought a boatload of them, and then decided to install them along my route!) I'd guess on average that I only have to stop at 3 of them...I only turn at 3 of the 11, the rest are drive-thru's.

The next 7 miles are 55mph limit, next 7 are 35/45, no stoplights, next 7 are 60mph interstate, last 2 are rural with one light to work.

In the 55/60 limits I do somewhere around 55-62mph.

Car rests on weekends!
Thanks for the run down... I think too that the lower speeds keep things in order & that your stops/starts aren't very unexpected like the city traffic I'm exposed to. Anyway, good job & do keep us posted on the spark gap & if that made any difference. Mine seems to have not, but I sure do appreciate the better performance I've seen over the past week & 1/2.
 

·
Premium Member
Joined
·
2,822 Posts
Nice!! I am sure you will see an improvement with the spark plug re gap. I am really glad I upped the gap and I'm only at .030 because I am tuned.
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #11 ·
Nice!! I am sure you will see an improvement with the spark plug re gap. I am really glad I upped the gap and I'm only at .030 because I am tuned.
OK...My last 400 miles on the most recent tank on this graph were post re-gapping to 0.035". We'll see how this tank goes and I'll update accordingly....

Text Font Technology Screenshot Electronic device


I had a nice upward trend that started happening when warm weather hit and I also turned 10K miles.
Best tank yet is still 40.4mpg...the most recent tank at 39mpg was the partial regap tank.
I regapped 100 miles into the tank and ended up at 39, which wasn't bad considering I ran the A/C some and
also had to deal with some road construction stoppages on my afternoon commute.
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #13 ·
Just filled up today. 45 mpg.
Nice!
I'm wondering if I can hit 45mpg stock. So far I am completely stock (K&N SRI still awaiting installation). Trifecta still in the plans.
I was wanting to wait to see where my average MPG leveled out before starting any fuel efficiency mods; but as you can see,
my averaga MPG's keeps rising.
 

·
Registered
Joined
·
468 Posts
I have the K&N and Trifecta tune.

And btw my mileage isn't from as someone who drives just on roads with 50-55 mph speed limits. I'm on city streets, then highway cruising at 62-65, and hit a max of 70 mph leading up to a bridge that I then largely coast up (hit the gas pedal enough so that the DIC sits around 40 mpg)

If not for that bridge, I'd probably get a few more mpg since I'd just leave it at 62-65 the whole way.
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #15 ·
Wish I could hit more highways too.
My average speed is usually 35-37mph at fill-up which puts me at about 63% city/37% highway.
I need to do a good road trip!
 

·
Administrator
Joined
·
15,844 Posts
I get better mileage in my commute than on road trips since I refuse to go 70 on a 70 mph freeway. I do 75. Still averaged 40.6 though at 75.
Same here. I can drive nicely enough in-town, with an average of speed typically 30-33 mph, to maintain a 40mpg+ calculated average at the pump. While highway driving should boost that significantly, I find that going 70-75mph to keep up with traffic actually skews my numbers a bit since my average speed goes up, but my fuel economy barely does.

I've also had to use A/C this entire last tank of gas, which I know will hurt my numbers quite a bit. I may have my first sub-40mpg tank in a long time when I fill up tonight.
 

·
Premium Member
Joined
·
25,595 Posts
Same here. I can drive nicely enough in-town, with an average of speed typically 30-33 mph, to maintain a 40mpg+ calculated average at the pump. While highway driving should boost that significantly, I find that going 70-75mph to keep up with traffic actually skews my numbers a bit since my average speed goes up, but my fuel economy barely does.

I've also had to use A/C this entire last tank of gas, which I know will hurt my numbers quite a bit. I may have my first sub-40mpg tank in a long time when I fill up tonight.
70-75 MPH on flat ground with no wind translates into 45-40 MPG, which is why your MPG numbers don't change. At 55, you'll see 50+ MPG. At 65, you'll see 47-48 MPG. The motor trend article comparing 40 MPG cars had a graph showing "theoretical" mpg limits vs. speed. For the Cruze ECO MT, those limits aren't just theoretical - they're real. I compared what I see at various speeds and found they matched almost exactly with what MT showed.

40 MPG Comparison Constant Speed Chart Photo 13
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #20 ·
Looks like I might hit 300 miles BEFORE the needle gets to the half tank mark this time...never seen that before. DIC currently estimating 44.3mpg....never had this high of an estimate this close to a half tank either. Maybe the re-gap is coming thru!
 
1 - 20 of 31 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top