Chevy Sonic 1.4L Engine Torque Curve

[ChrisJ]

I agree with Chris on this one. also, what is important is the horsepower in the destination gear. if you shift too soon then you are missing out on available horsepower at the bottom of the next gear.

that being said, I personally don't redline all that often because I don't have a racecar.

My car rarely sees 6k, only if I really need to get moving. I normally shift somewhere between 2 or 3k. Cruising is at as low of an rpm as gearing permits. Some roads I'm in 5th going 30mph.

 

[Eric Smit]

I'd be in 6th at 30 if I wanted mad MPG.

 

[rondoman]

I usually always shift around 3500-4000 range.

 

[ChrisJ]

I'd be in 6th at 30 if I wanted mad MPG.

Na, 6th just seems totally dead at 30, are you even at 1K at that point?

 

[sx sonic]

6th @ 30 is less than 1K RPM any less than a touch of throttle feels like lugging.

I'm usually in 6th at 40mph.

Usually shifting at 1500 rpm. Even in ECO mode I can merge off of most on ramps at 70mph shifting like that. Normally shifting at 4K RPMs is silly unless you want to break 100 mph at the end of an on ramp.

 

[Eric Smit]

nope, not even 1k. 95 MPG is hard to argue with.

 

[ChrisJ]

Speaking of eco, what is the "eco" light for in the Sonic tach? Does a euro model have eco mode or something?

 

[ChrisJ]

nope, not even 1k. 95 MPG is hard to argue with.

True, but burnt valves is another story. Not sure if its true but I've always been told lugging an engine can burn valves. True or false?

 

[$ub$onic]

Its hard on bearings if the engine is not built for it.

 

[Eric Smit]

Speaking of eco, what is the "eco" light for in the Sonic tach? Does a euro model have eco mode or something?

nope. useless light.

Lugging an engine can result in a burnt valve, but my engine isn't lugging. Not only that, but I don't often drive for stupid high MPG.

 

[ChrisJ]

nope. useless light.

Lugging an engine can result in a burnt valve, but my engine isn't lugging. Not only that, but I don't often drive for stupid high MPG.

Why does it burn valves? Years ago my dad kept telling me this and I ignored him. Later my Honda ATC-200X ended up with a leaky exhaust valve (exhaust glowing orange under normal riding), probably from me lugging it at times. I'm curious why it happens.

 

[rondoman]

I usually always shift around 3500-4000 range.

Oh ****, my bad.

I meant 2500-3000 range.

 

[rondoman]

StandardShift.com ? View topic - Why is Lugging Engine Bad?

 

[Eric Smit]

StandardShift.com ? View topic - Why is Lugging Engine Bad?

great link.

 

[ripper806]

There have been a few dyno charts scattered around the forum of stock and tuned 1.4t's. Unfournately they are hard to find and some of the links have disappeared.

Stock this engine starts falling off the power curve at around 5200 RPM. Tuned and with some intake plenum porting this engine continues to pull all the way to redline.

Not sure why having six speeds would be a waste. What would be different with a 5sp or heck even a 3sp? The extra gears aren't there for "2 fast 2 furious" driving. They simply allow a very tall final drive in top gear (read best mpg) and have even ratios between 1st and 6th (read even rpm drops between shifts).

IMHO a 5sp would be great in this car. Taller 1st gear, taller 2nd, 3 & 4th about the same ration and a Dth gear way taller than our current 6th gear. But the typical turn key driver would have complaints and questions about the tall 1st gear and huge jump to 5th because they don't understand the functional rationale behind it.
Hence why we have a 6sp

Well said! Port your intake manifolds!!! It is the way this engine is meant to run

 

[Blake1111]

My Sonic can get around 242 lb.ft at around 4Krpm