Chevrolet Cruze Forums banner
1 - 10 of 10 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.
 

·
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!
 

·
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.
 

·
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!
 

·
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!
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #23 ·
Maybe this is coincidence but looking at the numbers on FUELLY.COM it seems the RS cruze ground effects have some aerodynamic benefits, most of the RS cars seem to get better MPG than the normal non-eco cruzes.
Now that's a thought I don't think I've seen considered here.....maybe the RS does help with aerodynamics...

That said, coincidence or not, I set a new record with this morning's fill-up...first fill-up with a full-tank re-gap on the plugs (to 0.035").

Went 540 miles on a tank and re-filled with 13.256 gallons = 40.73mpg...trumps my old record (previous tank) of 40.3 by about .5mpg.
This, mind you, I will admit is with NO A/C whatsoever....
This thing goes so far between fill-ups....the temperature was in the mid-upper 80's when I filled up...so I suffered thru the past week of 100+ degree highs,
just to see what the MPG would be! LOL! Well, the A/C comes on today, so I'll get a feel for what effect the A/C will have on my mpg's.

BTW, when I filled up this morning, the DIC was estimating a range of 700 miles! That was a first too...
 
  • Like
Reactions: Starks8

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #25 ·
I'm a little hesitant to pass much judgement on the re-gap at this point...the re-gap may have helpt to the tune of 0.5-0.6mpg or so...not sure yet. Since I gotta start running the A/C, we may never know!
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #28 ·
CoughGETATUNECough LOL. It's next.. you might get... 42 MPG!

LOL Yeah, sweating for MPG is just not for me. Though admittedly I don't use A/C if it is a short in town trip I just do windows down. But when you get on the highway, its best to just close the windows and get comfortable. I keep mine at 72-74 when its on.. not too outrageous. My DIC reads 40+ on the highway with A/C at 55 mph CC turned on!

But for comparison gman, my commute is official now since I started my new gig. I drive 17 miles to work, about 13 are on a 55 mph highway and at 6:30 AM I can set the cruise control at the speed limit. When my tank is fresh, I get DIC values of 38+. The killer is for my job I have to make numerous short trips during the day (all less than 5 miles) which drags it down.. but im still getting ~32 MPG per tank! So now you have to get the tune so we can compare!
Well the AC does have quite an effect on the mpg...along with some more town driving...much like your short <5 mile hops!
I'm fortunate enough that I can stay parked from the time I arrive until I get ready to leave. My current tank, I'm going to
try an alternate route to and from work...it will add 3/4 mile to my commute each way, but will keep me off the interstate, so we'll see.

Looking at my previous 5 tanks:
38.8, 38.84, 40.34, 39.04, 40.74 mpg's respectively. All commute with no AC and a calculated 60% city/40% highway split.

My latest tank:
36.05mpg running AC on commute home from work about half the days, and more town driving at a 72% city/28% highway split.

As far as the tune...my plan is to get it in August at my one year anniversary of taking delivery of my Cruze.
Break in will be well behind me and I'll have a year of data to start comparing to..

Should I install the intake (K&N) at the same time as the tune?? I like to change things step by step...too many changes and any
resultant effects are hard correlate to said change(s)...

Guess we'll see next month! Maybe there'll be some specials out there!
 

·
FI Lunatic
Joined
·
1,380 Posts
Discussion Starter · #29 ·
Latest tank:
566 miles, low fuel warning on at 560 miles.
DIC estimate = 45.1mpg
Average Speed = 34.5mph
Calculated MPG = 41.15mpg

No A/C this tank.
 
1 - 10 of 10 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