[MP81]

I wonder if your mods, especially the 19 inch tires had an impact of fuel economy? I would guess it could have. Made a trip yesterday from Indy area to Fort Wayne and got 52 mpg on way up and then economy dropped on way home to 47 with a strong cross wind. My car is bone stock other than tint. Interesting as well, my last regen was 89 miles, this tank I am at 350 miles and at 20 grams and been very slow since I got fuel. I wonder if my car has winter fuel or if lower temps outside give me more miles per regen? Dramatic difference.

Those look to be pretty lightweight wheels - so I wouldn't be surprised if they're actually lighter than the OEM 17's. That said, the tires are more than likely far heavier than the factory Fuel Maxes. What size tire and what kind of tire are they?

 

[diesel]

Ok... Shall I set cruise control? I think there is a (mostly) flatish stretch on the way to Winston-Salem. I should be able to do this Sunday.

I have found that I get the best MPG with the cruise on

 

[obermd]

Ok... Shall I set cruise control? I think there is a (mostly) flatish stretch on the way to Winston-Salem. I should be able to do this Sunday.

I would use cruise control for this. The cruise control in the Cruze is the best I've ever seen.

 

[Tomko]

I would use cruise control for this. The cruise control in the Cruze is the best I've ever seen.

I agree. It is an excellent cruise control in my CTD.

 

[MP81]

Agreed. It's smooth, and if you were to re-engage cruise at a much lower speed, it doesn't immediately shoot to WOT in order to achieve said speed.

 

[Aussie]

Do you take the fuel usage off the DIC, or at the pump when you fill it? Cruise set at 110kph has my RPM at 1750. The Australian diesel has the 6T45 automatic and a 2.64 diff ratio.

 

[GMMillwright]

Never weighed the wheels/tires from factory or the TSWs. The 19s are rotary forged, so I'd guess they are relatively light. The tires aren't LRR and the added 1" in width does have an effect on the mileage. Taking all that into account, still not 100% satisfied. I drive the speed limit on the highway and baby it all the other times. Always looking for the next upshift and routinely see huge instantaneous mpgs. Just doesn't seem to materialize into 40+ averages per tank. Just frustrating.

 

[BrightParrot]

Do you take the fuel usage off the DIC, or at the pump when you fill it? Cruise set at 110kph has my RPM at 1750. The Australian diesel has the 6T45 automatic and a 2.64 diff ratio.

I've been using ACar on my phone, that does the calculations from mileage / gallons and I keep an eye on the DIC to get a general estimate as to how I am doing. The ACar app is what I am ultimately going by for the MPG per tank.

 

[IndyDiesel]

Never weighed the wheels/tires from factory or the TSWs. The 19s are rotary forged, so I'd guess they are relatively light. The tires aren't LRR and the added 1" in width does have an effect on the mileage. Taking all that into account, still not 100% satisfied. I drive the speed limit on the highway and baby it all the other times. Always looking for the next upshift and routinely see huge instantaneous mpgs. Just doesn't seem to materialize into 40+ averages per tank. Just frustrating.

Any chance the tires also changed the calibration of your speedometer and odometer? I am not familiar with what happens when you change tire size etc, maybe it changed your odometer to show less miles than actual miles traveled and that could make it look like your mileage sucks when maybe it doesn't? Just an idea.

 

[MP81]

Any chance the tires also changed the calibration of your speedometer and odometer? I am not familiar with what happens when you change tire size etc, maybe it changed your odometer to show less miles than actual miles traveled and that could make it look like your mileage sucks when maybe it doesn't? Just an idea.

If the tire diameter is not the same as the stocks 215/55R17s, then it will throw that all off - maybe a little, maybe a lot. Depends on the size of the new tires.

 

[2014Oilburner]

Honestly, I think I've found this car likes doing 70 more than doing 60. Driving to NC the last time (going for the Hypercruzer badge), it really seemed to be happier (fuel-wise) at 70-75 mph than at 55 or 60 mph.

That's not what I've found....at 55 mph my Cruze diesel got it's highest mileage I have ever seen getting 64.8 mpg in a 50 mile section on the DIC....My daily drive is also 37 miles one way to work and cruising 65 mph on pretty much level highway, I usually get mid 40's and as high as 51, until I get off the interstate and then it drops quickly back down to around 42/43 mpg....and will drop down into the mid 30's if you stay off the highway and do short local drives around home.

 

[GMMillwright]

stock: 215/55/17
new: 235/40/19

Only 3 revolutions per mile difference. Less than 0.5%.

 

[pandrad61]

Honestly, I think I've found this car likes doing 70 more than doing 60. Driving to NC the last time (going for the Hypercruzer badge), it really seemed to be happier (fuel-wise) at 70-75 mph than at 55 or 60 mph.

i did my 67.3 mpg run at 55-60mph cruise control the whole way. you also have to account for variables, tail wind can skew results ....

 

[Sperry]

Have to agree with the 55-60 mph best mileage..The only speed that might be better would 45 mph but I can't do that on the highway without getting slammed from behind..lol

 

[IndyDiesel]

stock: 215/55/17
new: 235/40/19

Only 3 revolutions per mile difference. Less than 0.5%.

Wow, pretty close, but wider I think you said and perhaps not low resistance, so maybe 2-5% difference

Still think you should be well above 40 on highway.

 

[GMMillwright]

Have only taken one long highway trip with the car so far. Didn't even have 1000 miles on the clock, so still not broken in at the time. Averaged mid 40s as expected. City and stop and go driving really drag down the average. Much more than when I drive my ECO (manual).

 

[obermd]

I've been using ACar on my phone, that does the calculations from mileage / gallons and I keep an eye on the DIC to get a general estimate as to how I am doing. The ACar app is what I am ultimately going by for the MPG per tank.

The only way to accurately measure MPG over the long haul is to record your odometer reading for each tank and the number of gallons filled. I use Excel and Fuelly for this purpose.

 

[IndyDiesel]

Have only taken one long highway trip with the car so far. Didn't even have 1000 miles on the clock, so still not broken in at the time. Averaged mid 40s as expected. City and stop and go driving really drag down the average. Much more than when I drive my ECO (manual).

I had a 14 eco manual and city driving that car was great, highway driving at moderate speeds it was really good, much above 70 mph it would drop off, the diesel does worse in the city with stop and go, it shines on a interstate drive at 60-70 mph. I would guess if you took a 100 mile trip where the wheels don't stop and set cruise at 65 it will do pretty well.

 

[boraz]

Honestly, I think I've found this car likes doing 70 more than doing 60. Driving to NC the last time (going for the Hypercruzer badge), it really seemed to be happier (fuel-wise) at 70-75 mph than at 55 or 60 mph.

crazy talk

yet to see a DIC pic of high mpg with high mph.

 

[Snipesy]

Progress! For 5 miles....