Displacement vs Cylinders
#62
There is probably a sweet spot for each configuration.
#65
Lexus Champion
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There's always been the argument; "no replacement for displacement". Lately due to governemnt regulations and emission standards coupled with social view the trend has been to downsize and add forced induction.
My question is, with all these automakers dropping say their 3.0-4.0 six in favor of a forced induction 2.0-2.9 four, why not downsize the displacement but retain the same cylinder count. Why don't we see 2.0L V6's? 3.0L V8's? (Some exceptions like the Mclaren 3.8L V8 and Lexus 4.8L V10 and excluding racing engines like F1)
Having the benefit of two extra cylinders especially in a luxury car adds/retains that refinement. The 2.5L V6 in the IS may get dinged for being 'slow' but then would you rather have a raspy four which is not as linear. As long as one understands the IS250 is a four cylinder competitor with two extra cylinders for refinement.
Any thoughts? Correlation between Displacement vs Cylinders?
Discuss!
My question is, with all these automakers dropping say their 3.0-4.0 six in favor of a forced induction 2.0-2.9 four, why not downsize the displacement but retain the same cylinder count. Why don't we see 2.0L V6's? 3.0L V8's? (Some exceptions like the Mclaren 3.8L V8 and Lexus 4.8L V10 and excluding racing engines like F1)
Having the benefit of two extra cylinders especially in a luxury car adds/retains that refinement. The 2.5L V6 in the IS may get dinged for being 'slow' but then would you rather have a raspy four which is not as linear. As long as one understands the IS250 is a four cylinder competitor with two extra cylinders for refinement.
Any thoughts? Correlation between Displacement vs Cylinders?
Discuss!
If it's not too late for long story short: 6 cylinder engine displacement cannot be reduced enough to meet future MPG requirements & maintain acceptable NVH standards. There is a definite point of diminishing returns in engine design. Ever notice how MBZ AMG vehicles use V-8's & the top luxury models are V-12's?
#66
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#67
All manufacturers are rushing to meet the coming CAFE MPG requirements. That means they must reduce engine displacement size, no other way to achieve required MPG goals. 2 engines, same displacement size using identical parts with the only design difference being 4cyl vs. 6cyl. The 4cyl will make more low rpm torque by virtue of it's larger cylinder. When you 1st start the engine the 1st cylinder that ignites has to have enough torque (twisting force) to rotate the crankshaft enough to ignite the next cylinder. Otherwise the engine will die & you have to use the starter motor to try again. Additional cylinders makes the ignitions closer in the firing order but the cylinders must be large enough to start the engine. Since the firing ignition events are closer together they are smoother, And since the parts are smaller & thus lighter they have less resistance to accelerating.
If it's not too late for long story short: 6 cylinder engine displacement cannot be reduced enough to meet future MPG requirements & maintain acceptable NVH standards. There is a definite point of diminishing returns in engine design. Ever notice how MBZ AMG vehicles use V-8's & the top luxury models are V-12's?
If it's not too late for long story short: 6 cylinder engine displacement cannot be reduced enough to meet future MPG requirements & maintain acceptable NVH standards. There is a definite point of diminishing returns in engine design. Ever notice how MBZ AMG vehicles use V-8's & the top luxury models are V-12's?
#68
Lexus Champion
Originally Posted by XPERIA
Hmmm looks plenty quick to me.. Pretty good actually for a 2500cc motor in a not so lightweight vehicle.
#69
Lead Lap
i'm seriously jealous of you, i wish i could enjoy life that easily. what's the fastest car you've ever been in if you don't mind me asking
#70
While the 3.5L trumps the 2.5, there's just something rewarding with revving the snot out of these 2.5 and being able to use the whole rpm range during every day driving. Can't really do that with the 3.5 (even less so with the 5.0) without hitting illegal speeds pretty quickly.
Yeah I know what you mean. But my main point being that the IS250 is more than powerful enough.
In fact the Camry 2.4L had more power than I ever needed. Yet the IS250 has an extra 50HP.
As a matter of fact after driving both 2IS IS250 & 200t back to back I actually prefer the 250 for its much, much smoother power delivery, I'd say its glass smooth. And also the fact that off the line its simply faster and offers a smoother drive in general.
In fact the Camry 2.4L had more power than I ever needed. Yet the IS250 has an extra 50HP.
As a matter of fact after driving both 2IS IS250 & 200t back to back I actually prefer the 250 for its much, much smoother power delivery, I'd say its glass smooth. And also the fact that off the line its simply faster and offers a smoother drive in general.
Anyway this isn't meant to be too much a discussion on the 4GR. As it stands there is one automaker that bolsters the thread topic well and that is Ford and it's new EcoBoost 2.7L V6. A great example of downsized displacement and cylinder retention. There are 4 applications and states of tune:
Ford F-150 325 hp (242 kW) @ 5750 rpm, 375 lb·ft (508 N·m) @ 3000 rpm
Lincoln MKX 335 hp (250 kW), 380 lb·ft (515 N·m)
Ford Edge Sport 315 hp (235 kW) @ 4,750, 350 lb·ft (475 N·m) @ 2,750 rpm
Ford Fusion Sport 325 hp (242 kW), 350 lb·ft (475 N·m)
So if most of today's six cylinders range 3.0L+, what Automaker might be the next to add a V6 of 2.9L or lower (could be NA or FI)?
#71
The 4GR-FSE was a decent engine. Unfortunately it was unloved by many simply because they didn't understand it's placement, nor did the carbon build up help its cause. The 2.5L V6 was released at a time when many premium automakers used 3.0L 6 cylinders but were transitioning to larger 6's. Benz had used a series of 2.5, 2.6 and 2.8L V6's before and during, and Acura had a spunky albeit raucous 2.4 I4 with 205hp. The 4GR with similar horsepower and more torque proved to be a gem of refinement and does like to be revved. In terms of horsepower it was adequate for a V6, but the reality of it was, the 4GR was more of a 4-cylinder competitor with similar displacement but two extra cylinders to keep things smooth, wheras the 3.5L serves as the real V6 offering. The GX460 is a prime example of a powertrain that is outclassed by a more modern V8 with it's V6 like horsepower (301hp). However view it as a V6 competitor and suddenly the GX stands out more because of it's extra cylinders 8 > 6 = more refined. As for the carbon build up, it would have helped somewhat to have port injection like it's larger 3.5L sibling, but truth is the vast majority of IS250 owners are not enthusiasts and simply drive point A to point B. If people would push their cars a little harder every now and then, they'd flush more potential particle build-up from the engine.
Anyway this isn't meant to be too much a discussion on the 4GR. As it stands there is one automaker that bolsters the thread topic well and that is Ford and it's new EcoBoost 2.7L V6. A great example of downsized displacement and cylinder retention. There are 4 applications and states of tune:
Ford F-150 325 hp (242 kW) @ 5750 rpm, 375 lb·ft (508 N·m) @ 3000 rpm
Lincoln MKX 335 hp (250 kW), 380 lb·ft (515 N·m)
Ford Edge Sport 315 hp (235 kW) @ 4,750, 350 lb·ft (475 N·m) @ 2,750 rpm
Ford Fusion Sport 325 hp (242 kW), 350 lb·ft (475 N·m)
So if most of today's six cylinders range 3.0L+, what Automaker might be the next to add a V6 of 2.9L or lower (could be NA or FI)?
Anyway this isn't meant to be too much a discussion on the 4GR. As it stands there is one automaker that bolsters the thread topic well and that is Ford and it's new EcoBoost 2.7L V6. A great example of downsized displacement and cylinder retention. There are 4 applications and states of tune:
Ford F-150 325 hp (242 kW) @ 5750 rpm, 375 lb·ft (508 N·m) @ 3000 rpm
Lincoln MKX 335 hp (250 kW), 380 lb·ft (515 N·m)
Ford Edge Sport 315 hp (235 kW) @ 4,750, 350 lb·ft (475 N·m) @ 2,750 rpm
Ford Fusion Sport 325 hp (242 kW), 350 lb·ft (475 N·m)
So if most of today's six cylinders range 3.0L+, what Automaker might be the next to add a V6 of 2.9L or lower (could be NA or FI)?
#72
Lexus Fanatic
It doesn't matter how smooth or what place the 2.5 had or if people did not understand the motor. It was a dog in the IS and premium fuel didn't help. My sister had that set up, underpowered as hell for a V6.
#74
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Here's a very detailed and informative presentation of the new CX-9, in particular it's new 2.5 turbo.
It's discussed by the Mazda engineer himself and he does a great job explaining the new techniques used in this new powerplant.
Warning: You will want to buy one after watching.
It's discussed by the Mazda engineer himself and he does a great job explaining the new techniques used in this new powerplant.
Warning: You will want to buy one after watching.
#75
Didn't help do what? The IS250 became the benchmark for smaller engines that other such as infinity tried to duplicate.