increase mileage in our cars? Arguing with a friend over this. LOL Yes I searched, but he wanted me to post.
-
Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.
Can a supercharger or turbo...
- Thread starter Fatal Lightning
- Start date
- Joined
- 21 January 2005
- Messages
- 1,384
I think my case mpg would go up. I wouldn't have to downshift from 6th to 3rd to pass anymore on the highway. I would also be more apt to short shift at 4k instead of winding it up to 8k on a regular basis.
No. both of these will increase the mass of air in the cylinders, which will need a similar increase in the amount of fuel injected into the cylinders.
yes... but I think having more power would change how you drive the car on a daily basis. As I said, I would be more apt to short shift when driving.
I think it's up to the tune.
LSx cars seem to gain 2~MPGs while cruising with blowers.
The issue is more of a matter of trying NOT to be more of a lead foot.
LSx cars seem to gain 2~MPGs while cruising with blowers.
The issue is more of a matter of trying NOT to be more of a lead foot.
Think of it this way. The variance in MPG varies much more in an FI car between cruising/light throttle vs. hard/heavy throttle. You'll see a much bigger swing in mpg compared to N/A. In this scenario one could make the argument between Turbo and SC even. AFAIK I think SC is more efficient under these conditions.
On my S/C truck daily driver, I get 1-3 mpg better in town and up to 5-6mpg better in hwy cruise mode. I even get better mpg with a full load as long as i'm easy on the right foot. Just let the compressed air do it's work. I've been getting such good mileage lately i'm concerned i'm running lean which is a different story.
When i'm on the gas... I get noticeably worse mpg.
On my S/C truck daily driver, I get 1-3 mpg better in town and up to 5-6mpg better in hwy cruise mode. I even get better mpg with a full load as long as i'm easy on the right foot. Just let the compressed air do it's work. I've been getting such good mileage lately i'm concerned i'm running lean which is a different story.
When i'm on the gas... I get noticeably worse mpg.
Forget driving style and all other varying factors. This is a simple math question. The more efficient the engine, the more power it produces from one gallon of gasoline. The more power it generates, the further it will move the car (under ideal driving conditions).
In general, a turbocharger captures wasted exhaust energy that is normally lost to the atmosphere, and makes the engine more thermally efficient. A supercharger creates more power by creating extra parasitic drag on the motor. Although it is possible that at certain RPM's and under a certain load (both sustained) a supercharged motor will have a higher peak of efficiency than a similar NA or turbocharged engine will, it is overall unlikely. A turbocharged engine is generally more efficient across the entire RPM spectrum. So with a standard "transmission", the turbocharged motor of equal design will generally create more power from every gallon of gasoline.
This is all general. There are many factors of course, like the terrain, the weight of the car, the transmission, the load, etc. Efficiency is not the same all the time. There are peaks and dips. If you create a situation where the peak can be maintained on one design, it will outdo the other two designs. In other words a supercharged 3.2 liter at 2750 RPM's carrying a certain load (weight, gearing, terrain, etc.) may be more efficient than the same engine with a certain turbocharger with the same load. Same with NA. Each design type will peak at a certain point, and each peak will be different. But driving inherently means you will not be able to maintain the peak for very long at all.
So the answer is not simple. It depends on the load, the tune and the transmission (even if driving style is mathematically perfect)... but to make it simple, I would just summarize and say yes to the turbo under most conditions, and no to the supercharger... this is simply based on what they are using as a source of energy.
By the way an electric motor blows all of these out of the water. It is generally close to 30% more efficient than all ICE (internal combustion engine) designs. The problem has never been one of efficiency but one of storage. A gallon of gasoline packs a lot of energy, much more so than 6 pounds worth of battery. If the battery issue is solved, looking strictly at numbers, ICE's (including the more efficient Diesels) are archaic.
In general, a turbocharger captures wasted exhaust energy that is normally lost to the atmosphere, and makes the engine more thermally efficient. A supercharger creates more power by creating extra parasitic drag on the motor. Although it is possible that at certain RPM's and under a certain load (both sustained) a supercharged motor will have a higher peak of efficiency than a similar NA or turbocharged engine will, it is overall unlikely. A turbocharged engine is generally more efficient across the entire RPM spectrum. So with a standard "transmission", the turbocharged motor of equal design will generally create more power from every gallon of gasoline.
This is all general. There are many factors of course, like the terrain, the weight of the car, the transmission, the load, etc. Efficiency is not the same all the time. There are peaks and dips. If you create a situation where the peak can be maintained on one design, it will outdo the other two designs. In other words a supercharged 3.2 liter at 2750 RPM's carrying a certain load (weight, gearing, terrain, etc.) may be more efficient than the same engine with a certain turbocharger with the same load. Same with NA. Each design type will peak at a certain point, and each peak will be different. But driving inherently means you will not be able to maintain the peak for very long at all.
So the answer is not simple. It depends on the load, the tune and the transmission (even if driving style is mathematically perfect)... but to make it simple, I would just summarize and say yes to the turbo under most conditions, and no to the supercharger... this is simply based on what they are using as a source of energy.
By the way an electric motor blows all of these out of the water. It is generally close to 30% more efficient than all ICE (internal combustion engine) designs. The problem has never been one of efficiency but one of storage. A gallon of gasoline packs a lot of energy, much more so than 6 pounds worth of battery. If the battery issue is solved, looking strictly at numbers, ICE's (including the more efficient Diesels) are archaic.
Last edited:
Don't forgot the new under development super small displacement FI engines.
The Chevrolet Cruze will begin arriving at US dealerships in September. The 2011 Chevrolet Cruze is powered by a new generation of small-displacement four-cylinder engines, including the Ecotec 1.4L turbo and the Ecotec 1.8L. The Ecotec 1.4L turbo is standard on Eco (earlier post), LT and LTZ models and helps the Cruze Eco achieve up to an estimated 40 mpg on the highway (with a standard six-speed manual transmission), which is expected to be the best fuel economy in the compact car segment.
The Chevrolet Cruze will begin arriving at US dealerships in September. The 2011 Chevrolet Cruze is powered by a new generation of small-displacement four-cylinder engines, including the Ecotec 1.4L turbo and the Ecotec 1.8L. The Ecotec 1.4L turbo is standard on Eco (earlier post), LT and LTZ models and helps the Cruze Eco achieve up to an estimated 40 mpg on the highway (with a standard six-speed manual transmission), which is expected to be the best fuel economy in the compact car segment.
I actually have a few friends and know some others that have gain gas milage with turbo. It also depends on the tuner.
- Joined
- 21 January 2005
- Messages
- 1,384
LOL. That blower would probably require 100 HP just to turn the impellers.
IF you drive normally and your driving style changes like the captain says (and it most likely will) then yes, you mileage will get better - I have noticed this with my own car. If on the other hand, your lead foot gets the best of you - well I'm sure you can figure it out...
I noticed my mileage went up about 1mpg when I got my turbo put on.. when I drive normally. When I drive like a crazed madman (more often than not lately) it is about 2mpg lower than before.
- Joined
- 10 August 2010
- Messages
- 633
it's all in the tune. adding the turbocharger itself will likely not yield better gas mileage in itself but when you turbocharge the car you will be getting it tuned. with a quality tune there is no reason the car shouldn't be capable of achieving stock gas mileage or better.
As others have said, Turbochargers converts wasted exhaust energy to compress air to make more power. Driving under 'normal'/daily circumstances, it is possible to get an across-the-board improvement in MPG, but it can also get much worse with a heavy right foot. Turbos also have a scavenging effect that superchargers do not. Superchargers are terribly inefficient concepts compared to turbos.
when i had my 240sx, i was getting 320 miles before my fuel light came on. i put on a turbo with light boost and got up to the 380-400 range.
I guess I can't speculate about adding a turbo to a non-turbo car. . I can say that on my old Jetta 1.8Turbo and my Mazdaspeed 3 (2.3L turbo) which came factory turboed, that if I'm in positive boost, my gas mileage goes down.
In those cars, in order to really generate boost, you need to really get the gas pedal down (meaning using more gas). You can technically accelerate without having the boost come up much at all. The gas mileage on my Mazdaspeed3 ranges from a highway best (drive to Vegas) of ~30mpg, to a worst of 7mpg (track day). On average a mixed highway/city gets me ~25-26mpg.
I would say it's hard to say. . because it's not an apples to apples comparison. Generally when you add a turbo, you're changing the tuning, compression, running different injectors, etc. . . with that all said, I would think that the gas mileage would go down or stay about the same with a turbo when driving non-aggressively. Driving aggressively or semi aggressively will definitely put the turbo at a disadvantage for gas mileage.
In those cars, in order to really generate boost, you need to really get the gas pedal down (meaning using more gas). You can technically accelerate without having the boost come up much at all. The gas mileage on my Mazdaspeed3 ranges from a highway best (drive to Vegas) of ~30mpg, to a worst of 7mpg (track day). On average a mixed highway/city gets me ~25-26mpg.
I would say it's hard to say. . because it's not an apples to apples comparison. Generally when you add a turbo, you're changing the tuning, compression, running different injectors, etc. . . with that all said, I would think that the gas mileage would go down or stay about the same with a turbo when driving non-aggressively. Driving aggressively or semi aggressively will definitely put the turbo at a disadvantage for gas mileage.
COULD it? yes. but i wager that your MPG will go down for the first few months of installing it (mine would :biggrin
ex MR2 turbo owner chiming in here; i used to get great MPG cruising on the highway (out of boost) 32-35mpg in town or on track was a much less happy number
ex MR2 turbo owner chiming in here; i used to get great MPG cruising on the highway (out of boost) 32-35mpg in town or on track was a much less happy numberSimilar threads
