MPG Master thread. MPG tips, questions, explanation, and concerns in here.
- Thread starter sx sonic
- Start date
ChrisJ
Active member
Even at full output the alternator only consumes 2.5 HP or so. For DRLs alone you're talking something like 1/15th of a hp.
The only way I could see being able to document that difference is on a dyno running 24\7 for several days with and without DRLs in a fixed environment.
Otherwise, ambient temperature change alone should have a bigger difference.
Scot
Athletic Supporter
You're thinking about it entirely wrong; Yes, the amount of power consumed by the alternator is small to overall engine output, but not to the power needed to drive the vehicle down the road. It takes about 11 horsepower to move a Sonic at 50 mph, so changes as small as electrical loads *do* make a difference. Now, if you spend your time driving ALL highway miles, it will be hard to see in your overall fuel economy - but I spend plenty of time at 50 mph and slower - and I believe I am seeing a difference.
Heck - back in 2003, I was working for Ford on the Lincoln LS - we changed over to using 0W-20 engine oil (from 5W-30) as the reduced pumping losses in the lubrication system bought us 1/10th of a MPG.
It's funny; just like building a bicycle to be the lightest it can possibly be, increasing fuel economy has come down to whittling away at the problem a little bit at a time. Most of my bicycles have titanium and aluminum bolts instead of steel. Sure - the weight difference of one bolt may be only two to five grams lighter, but all added together, I've shaved nearly half a pound off the weight of one of my bicycles.
ChrisJ
Active member
You're thinking about it entirely wrong; Yes, the amount of power consumed by the alternator is small to overall engine output, but not to the power needed to drive the vehicle down the road. It takes about 11 horsepower to move a Sonic at 50 mph, so changes as small as electrical loads *do* make a difference. Now, if you spend your time driving ALL highway miles, it will be hard to see in your overall fuel economy - but I spend plenty of time at 50 mph and slower - and I believe I am seeing a difference.
Heck - back in 2003, I was working for Ford on the Lincoln LS - we changed over to using 0W-20 engine oil (from 5W-30) as the reduced pumping losses in the lubrication system bought us 1/10th of a MPG.
It's funny; just like building a bicycle to be the lightest it can possibly be, increasing fuel economy has come down to whittling away at the problem a little bit at a time. Most of my bicycles have titanium and aluminum bolts instead of steel. Sure - the weight difference of one bolt may be only two to five grams lighter, but all added together, I've shaved nearly half a pound off the weight of one of my bicycles.
Two questions,
Why does Honda use *20 oil and GM uses *30?
I'd love t run 0w20 in the 1.4.
Second question, are you sure it's only 11hp @ 50mph? I ask because a stock Ford model A with 40HP can only do 60mph floored and weighs 2100lbs.
Of course I'm sure wind resistance is a lot more but I didn't think that much more?
Scot
Athletic Supporter
Two questions,
Why does Honda use *20 oil and GM uses *30?
I'd love t run 0w20 in the 1.4.
Second question, are you sure it's only 11hp @ 50mph? I ask because a stock Ford model A with 40HP can only do 60mph floored and weighs 2100lbs.
Of course I'm sure wind resistance is a lot more but I didn't think that much more?
I can't say why some companies choose some of the things they do; when we first went with 0W-20, I was certain I would fail an engine or two doing development testing in the desert. Didn't. Engines we tore down didn't show any excessive wear either.
As for the HP @ 50, 11 hp is about it. Reasons why there are differences in a Sonic and a Model A? A few that come to mind:
* Drag / frontal area
* the model A HP was gross, the sonic is SAE certified net (i.e. there is less than 40 HP in the Ford)
* greater mechanical losses everywhere in the model A
shorebreeze
Member
And any difference between the standard blended oil and pure synthetic? Other than frequency of oil change?
calmb4dastorm
New member
I've had my Sonic 1.4T for about a year now and figured now is the best time to share my findings thus far:
-What MPG are you getting? How are you tracking it, DIC display, hand calc?
I generally average between 32-35mpg durring the week and 35-40 on weekends in town on Military, QWIC Serv, and Valero 87 Octane. DIC. These are cheap gas in Norther California. I've tried 76, Chevron, and Arco fuels with less mpgs. I've also tried 89 and 91 Octanes; also lower mpgs.
- What fuel economy are you expecting and why?
I was expecting 35mpg and more based on Highway ratings of 40mpg, however I know most of these ratings are done at either 55mph or 65mph. I can't drive so slow.
- What are the approximate outside air temps?
Anywhere between 40-110 degrees Fahrenheit. Generally, my average mpgs stay between 32-35mpg.
- How long are your trips?
5 days a week a drive 65 miles to work and 65 miles from work. I'd say about 80% of my trips are at least 30 miles plus. (I'm already knocking on 30,000 miles )
- How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving?
Primarily Highway at 70-80mph (day) and 75 (night 1am or later). I tend to drive faster during the day even with traffic and tend to do better during the day trips. I'm really thinking the air pockets durring the day are what's helping me. In town I drive 35-60mph (depends on which street I'm on). Usually I avoid stop and go but it is inevitable.
- What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)
Hilly highway. 2 steep hills that force me down to 5th or even 4th gear (normally 5th with my usual fuels; 4th gear with the "better" fuels). Flat city.
- What are your tire pressures?
35psi
- Make, model, year, engine and transmission of previous car?
'03 Silverado 4.8L V8; 40 mile trips one way; average 21mpg on 87
'06 Cobalt SS 2.0SC; 35 mile trips one way; average 26mpg on 91
'91 Geo Storm 1.5L 3cylinder; 5 mile trips one way; average 30mpg on 87
- How are you trying to drive
My normal. I only drive as slow as traffic. 10-15 mph over limit is not only more comfortable but gets me to point B sooner (usually by 10-15 minutes). Minor PTSD keeps me from allowing myself to be on the road longer than necessary.
- Are you using the A/C?
Only over 70 degrees unless using to defog windshield. I do crack all 4 windows when I smoke and I smoke a lot :blankface:
- Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15).
all original
In conclusion, I would say that the "Cheap" gas stations with 87 octane does better with power and mpg than the "Good" gas stations or any gas station with 89 or 91 octane.
-What MPG are you getting? How are you tracking it, DIC display, hand calc?
I generally average between 32-35mpg durring the week and 35-40 on weekends in town on Military, QWIC Serv, and Valero 87 Octane. DIC. These are cheap gas in Norther California. I've tried 76, Chevron, and Arco fuels with less mpgs. I've also tried 89 and 91 Octanes; also lower mpgs.
- What fuel economy are you expecting and why?
I was expecting 35mpg and more based on Highway ratings of 40mpg, however I know most of these ratings are done at either 55mph or 65mph. I can't drive so slow.
- What are the approximate outside air temps?
Anywhere between 40-110 degrees Fahrenheit. Generally, my average mpgs stay between 32-35mpg.
- How long are your trips?
5 days a week a drive 65 miles to work and 65 miles from work. I'd say about 80% of my trips are at least 30 miles plus. (I'm already knocking on 30,000 miles
) - How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving?
Primarily Highway at 70-80mph (day) and 75 (night 1am or later). I tend to drive faster during the day even with traffic and tend to do better during the day trips. I'm really thinking the air pockets durring the day are what's helping me. In town I drive 35-60mph (depends on which street I'm on). Usually I avoid stop and go but it is inevitable.
- What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)
Hilly highway. 2 steep hills that force me down to 5th or even 4th gear (normally 5th with my usual fuels; 4th gear with the "better" fuels). Flat city.
- What are your tire pressures?
35psi
- Make, model, year, engine and transmission of previous car?
'03 Silverado 4.8L V8; 40 mile trips one way; average 21mpg on 87
'06 Cobalt SS 2.0SC; 35 mile trips one way; average 26mpg on 91
'91 Geo Storm 1.5L 3cylinder; 5 mile trips one way; average 30mpg on 87
- How are you trying to drive
My normal. I only drive as slow as traffic. 10-15 mph over limit is not only more comfortable but gets me to point B sooner (usually by 10-15 minutes). Minor PTSD keeps me from allowing myself to be on the road longer than necessary.
- Are you using the A/C?
Only over 70 degrees unless using to defog windshield. I do crack all 4 windows when I smoke and I smoke a lot :blankface:
- Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15).
all original
In conclusion, I would say that the "Cheap" gas stations with 87 octane does better with power and mpg than the "Good" gas stations or any gas station with 89 or 91 octane.
The Champ
New member
It's not a typo.
The Driver Information Center (DIC) can display the MPG average, the MPH average, the miles remaining and a timer. Check your owners manual and learn how to switch the display.
I've had my Sonic 1.4T for about a year now and figured now is the best time to share my findings thus far:
-What MPG are you getting? How are you tracking it, DIC display, hand calc?
I generally average between 32-35mpg durring the week and 35-40 on weekends in town on Military, QWIC Serv, and Valero 87 Octane. DIC. These are cheap gas in Norther California. I've tried 76, Chevron, and Arco fuels with less mpgs. I've also tried 89 and 91 Octanes; also lower mpgs.
- What fuel economy are you expecting and why?
I was expecting 35mpg and more based on Highway ratings of 40mpg, however I know most of these ratings are done at either 55mph or 65mph. I can't drive so slow.
- What are the approximate outside air temps?
Anywhere between 40-110 degrees Fahrenheit. Generally, my average mpgs stay between 32-35mpg.
- How long are your trips?
5 days a week a drive 65 miles to work and 65 miles from work. I'd say about 80% of my trips are at least 30 miles plus. (I'm already knocking on 30,000 miles
- How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving?
Primarily Highway at 70-80mph (day) and 75 (night 1am or later). I tend to drive faster during the day even with traffic and tend to do better during the day trips. I'm really thinking the air pockets durring the day are what's helping me. In town I drive 35-60mph (depends on which street I'm on). Usually I avoid stop and go but it is inevitable.
- What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)
Hilly highway. 2 steep hills that force me down to 5th or even 4th gear (normally 5th with my usual fuels; 4th gear with the "better" fuels). Flat city.
- What are your tire pressures?
35psi
- Make, model, year, engine and transmission of previous car?
'03 Silverado 4.8L V8; 40 mile trips one way; average 21mpg on 87
'06 Cobalt SS 2.0SC; 35 mile trips one way; average 26mpg on 91
'91 Geo Storm 1.5L 3cylinder; 5 mile trips one way; average 30mpg on 87
- How are you trying to drive
My normal. I only drive as slow as traffic. 10-15 mph over limit is not only more comfortable but gets me to point B sooner (usually by 10-15 minutes). Minor PTSD keeps me from allowing myself to be on the road longer than necessary.
- Are you using the A/C?
Only over 70 degrees unless using to defog windshield. I do crack all 4 windows when I smoke and I smoke a lot :blankface:
- Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15).
all original
In conclusion, I would say that the "Cheap" gas stations with 87 octane does better with power and mpg than the "Good" gas stations or any gas station with 89 or 91 octane.
This is good to know. Thank you for this write up. I travel 100 miles a day to work and back round trip. I've always used 93 Octane. I was educated on another post about the benefits ( or lack of ) for using 93.
I have 3500 miles now. And after this tank I will try this approach. Now I'm in Miami. So the ac is mandatory right now every day. We have similar driving styles so this should help.
However , I am worried about serious knocking. Is this a result of using 87? Should I continue using 93 to avoid this?
Any info would really help. Thanks !
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moneyman90
New member
I know it was somewhat covered here but is it better to just stick with the 87? I have a 2017 LT Turbo and I just stopped yesterday and got 89.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
yevgenievich
Member
-What MPG are you getting? How are you tracking it, DIC display, hand calc?
47 on DIC, 37 hand calc
- What fuel economy are you expecting and why?
Greater than 30
- What are the approximate outside air temps?
20* to 40*, 48* on direct sun light
- How long are your trips?
10 miles or less
- How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving?
All city, but not too much stop/go, avg speed 45mph not including stops.
- What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)
Gentle hills
- What are your tire pressures?
36
- Make, model, year, engine and transmission of previous car?What did you actually get on the same trips/commute? A lot here:
1967 Camaro(boosted big block) - 3mpg
1988 C3500(big block) - 8mpg
1991 V2500(suburban) - 10mpg
1992 Dodge Stealth(sohc) - 20mpg
1989 Trans Am(ls1/t56) - 18mpg
1997 C3500(big block) - 16mpg
1985 C1500(rev happy small block) - 8mpg
1976 Vulcan 750(two wheels) - 40mpg
- How are you trying to drive
Slow on accel/brake and faster on turns,
Most of the vehicles listed above were driven with faster accel
- Are you using the A/C?
If it is needed
- Are you using the factory tires and wheels? If not, please indicate tire make, model and size
Factory 15's
47 on DIC, 37 hand calc
- What fuel economy are you expecting and why?
Greater than 30
- What are the approximate outside air temps?
20* to 40*, 48* on direct sun light
- How long are your trips?
10 miles or less
- How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving?
All city, but not too much stop/go, avg speed 45mph not including stops.
- What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)
Gentle hills
- What are your tire pressures?
36
- Make, model, year, engine and transmission of previous car?What did you actually get on the same trips/commute? A lot here:
1967 Camaro(boosted big block) - 3mpg
1988 C3500(big block) - 8mpg
1991 V2500(suburban) - 10mpg
1992 Dodge Stealth(sohc) - 20mpg
1989 Trans Am(ls1/t56) - 18mpg
1997 C3500(big block) - 16mpg
1985 C1500(rev happy small block) - 8mpg
1976 Vulcan 750(two wheels) - 40mpg
- How are you trying to drive
Slow on accel/brake and faster on turns,
Most of the vehicles listed above were driven with faster accel
- Are you using the A/C?
If it is needed
- Are you using the factory tires and wheels? If not, please indicate tire make, model and size
Factory 15's
