13 replies to this topic

[Mete Goktepe]

Hello dear friends,

I just want to have your opinion about the fuel consumption discussion which is ongoing for many years.. most people say and believe that a turbo care would use double quantity or fuel when compared to an n/a car.. if we take my '95 850 Glt with auto trans for an example the 2.5 engine has 170 hp's but the torque is 220nm. and my uncle has an '97 S70 T5 with auto trans which is 225 hp's and 300nm of torque.. so would this turbo car will use more or less gasoline when compared to my N/A 850? I believe it could use less since the car has a serious torque advantage and this will help the car pull better on all circumctances.. if I'm going uphill I have to keep the engine at 2500 rpms at least.. 3000 would be better. but on the same circumctances the turbo would pull at 2000 easily without requiring me to give more throttle..but the disadvantage is the turbo accelarates faster all the time.. seducing me to floor the accelerator.. this time the fuel will be naturally doubled..

so what are your comments.. I may think of buying an S70 which is turbo just to have a really fast car at hand..


thanks

[BananaRep]

The turbo uses more.
When I switched from my 850 GLT 5 sp to the V70 T5 auto, I estimated that fuel consumption increased by about 50%.

[Kevin.]

Honestly, I think that turbo's actually get on the average BETTER mileage, especially on the highway

[Zappo]

NA will be better, but not twice as good.

It really depends on how the cars are driven. Most on there that move from NA to turbo will use the new found power a lot and in turn increase their fuel consumption.

[850wagonT5]

Hello dear friends,

I just want to have your opinion about the fuel consumption discussion which is ongoing for many years.. most people say and believe that a turbo care would use double quantity or fuel when compared to an n/a car.. if we take my '95 850 Glt with auto trans for an example the 2.5 engine has 170 hp's but the torque is 220nm. and my uncle has an '97 S70 T5 with auto trans which is 225 hp's and 300nm of torque.. so would this turbo car will use more or less gasoline when compared to my N/A 850? I believe it could use less since the car has a serious torque advantage and this will help the car pull better on all circumctances.. if I'm going uphill I have to keep the engine at 2500 rpms at least.. 3000 would be better. but on the same circumctances the turbo would pull at 2000 easily without requiring me to give more throttle..but the disadvantage is the turbo accelarates faster all the time.. seducing me to floor the accelerator.. this time the fuel will be naturally doubled..

so what are your comments.. I may think of buying an S70 which is turbo just to have a really fast car at hand..


thanks

Nobody who has any clue what they're talking about would claim that a turbo car uses "double" the amount of fuel compared to an N/A car. This is complete hogwash.

http://www.fueleconomy.gov/feg/bymodel/1996_Volvo_850.shtml

...for the record, I normally averaged 24-27mpg per tank full, calculated properly by complete fill ups and odometer tracking, in my Turbo wagon with at least half highway driving (yes...better than the EPA estimates). Driving style/habits has A LOT more to do with fuel economy than turbo vs N/A. If you're doing all city driving and you have a lead foot, expect your fuel mileage to be poor.

If a turbo car used *double* the fuel, it would have double-sized injectors, a double-size fuel tank, etc. It doesn't, though. The fuel tank and fuel injectors are only a few percent larger than the non-turbo counterpart. This is the actual difference in fuel used (1mpg difference in the city, 2mpg difference on the highway - according to the link above). Not anywhere near double.

The turbo uses more.
When I switched from my 850 GLT 5 sp to the V70 T5 auto, I estimated that fuel consumption increased by about 50%.

Something is wrong with your car if your fuel consumption went up by 50%.

so what are your comments.. I may think of buying an S70 which is turbo just to have a really fast car at hand..


thanks

...if you're thinking of getting it so you have a "fast car," why do you care about fuel economy?! Sounds like you plan to drive it hard...so yes, fuel mileage will suffer a proportionate amount.

[bergmjs]

The best I ever got in my NA was 25mpg highway. I get 26-29mpg in my turbo depending on how many on/off ramps I take . I calculated both from proper fill-ups and odometer readings then compared to the instrument cluster reading. The cluster is actually always within 1mpg of the calculated value.

[BananaRep]

Let me clarify that my estimate was based on city driving, filling up once a week. Both cars were properly maintained and with stage 0 complete.

[Burn-E]

With 165k miles on my NA 1998 S70 with auto transmission I can easily achieve 31 mpg all highway driving. Tested this a year ago with a long road trip I had to do. When it's largely city driving I see 21 mpg in the winter (Illinois fuel additives) and 23 mpg during the summer.

My quite non-stock C70 T5 with manual transmission averages 22 mpg. I haven't done any highway road trips long enough to determine highway only.

[Kevin.]

On road trips I average out to about 33 mpg at 65 mph. 75 mph average gets me about 25

[Mete Goktepe]

I started this topic because I think the 850 N/A's perfomance on driving uphill is poor.. its average.. if the Air conditioning is on when driving uphills the the performance is worse.. I wonder what would happen if I buy a T5 and drive it on the same conditions?

for example you driving on a hill which is a mile long.. there are two cars one of them is the 850 N/A the other is t5.. the N/A will need additional throttle on halfway to pull better.. will the t5 pull without the need of additional throttle because of the torque or we'll still have to give additional throttle to make the car pull?

I especially want to know will a t5 climg a hill with stability? or will it still need more throttle? because I tested my uncles s70 t5 on the same road which I use almost everyday the s70 pulled very easily with 2100 rpms with a speed of 40 miles without giving more throttle but my glt needed to have 2500-2800 rpms to pull that easily..with the same speed yes the turbo makes a difference I know but is that that different? and isnt it true if a car pulls easily with 2100 rpms that car will use less fuel when compared to N/A car?

its been too much questions but I just want to clear the questions on my mind..

thank you all

[bergmjs]

Before you spool up the turbo the T5 engine is actually less powerful than the NA due to a decreased compression ratio and decreased displacement. So, you need to spin the engine up to 2.5k-3k before the turbo spools and you start getting that extra kick out of it, which, in-turn, consumes more fuel.

You can however, if done properly, get a higher volumetric efficiency out of a turbocharged engine than an NA, thus producing more power out of the same sized engine, or using less fuel for the same power. But again, that depends on your entire setup.

If you really want the sweet spot of performance to fuel economy, get a T5, manual swap it and buy ARD's fuel economy tune. You still get the extra little kick from the turbo, but it's tuned for fuel efficiency rather than power and the manual transmission is more efficient and more fun as well.

[850wagonT5]

Just drive the car and check your mileage.

...and there's your answer.

[bergmjs]

Just drive the car and check your mileage.

...and there's your answer.

Because he obviously has an NA and a turbo prior to selecting if he wants to upgrade from his NA to a turbo to compare.

[850wagonT5]

Because he obviously has an NA and a turbo prior to selecting if he wants to upgrade from his NA to a turbo to compare.

He said he wants a "fast car." He's heard from half a dozen people telling him pretty much the same thing that the EPA MPG estimates say. It's not a significant difference, unless you drive it hard.

/thread.