Torque Curve b/w V6 vs. V8

[Thai]

Sources of torque curve of the two engines:

V6 = www.tundrasolutions.com/forums/attachments/tacoma/11846d1142555992-engine-overview-1grfeeng.pdf

(see page 3)

V8 (prior to VVTi) = http://www.toyota120.com/GenDocs/2003_4Runner.pdf

(see page 7)

Disclaimer: this is all based on me drawing a line down and across (with some extrapolation)...so, the torque figures are not 100% accurate, but should give you an idea of torque curve differences between the two engines.

4.0 V6 1GR-FE approximate torque % (torque at specific RPM divided by max torque):

Max Torque listed is 282 ft/lbs at 3800 rpms

1000 rpm = 220 ft/lbs over 282 ft/lbs = 78% of max torque
2000 rpm = 250/282 = 88.6%
3000 rpm = 260/282 = 92.8%
4000 rpm = 275/282 = 97.5%
5000 rpm = 255/282 = 90.4%

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4.7L V8 2UZ-FE:

Max Torque listed is 320 ft/lbs at 3400 rpms

1000 rpm = 270/320 = 84.4%
2000 rpm = 285/320 = 89.1%
3000 rpm = 310/320 = 96.8%
4000 rpm = 290/320 = 90.6%
5000 rpm = 230/320 = 71.9%

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Conclusion: from my point of view, the V8 engine (non-VVTi) definitely is designed for low end power...the torque curve clearly favors low rpm torque over high rpm power. The V6, on the other hand, is a more modern design with VVTi...and this VVTi technology is clearly reflected in its flatter torque curve (shocking finding for me!). The 4.7L V8 gives you a lot of torque early, but falls pretty quickly after it peaks at 3400 rpm.

The V6 clearly cannot match the V8's low end torque production...because there is "no replacement for displacement." That much is true. However, the V6 numbers are far from being peaky nor anemic...it produces a respectable 78% of its max torque as low as 1000 rpm...and jumps up to 88.6% (matching the V8!) at 2000 rpm. What is nice is that the torque stays there after it peaks at 3800 rpm...all the way till 5000 rpm (90.4%)...you can thank VVTi for that!

What does this mean? I have no idea. You guys can come to your own conclusion. Many will argue that the V8 produces power where a truck needs it the most...and where off-roading needs it the most. Others will argue that the V6 is fully competent in the lower end, yet still provides excellent response at higher rpms. Your miles may vary....

NOTE: in 2005, Toyota added VVTi to the 4.7L V8 engine...unfortunately, i do not have the torque curve for that engine. I am sure that VVTi would improve the 4.7L V8 engine torque curve at higher rpms, thus making it as flat as the V6's curve.

 

[ToyTech99]

Thanks for the info. I was going to try and find it myself, so you just saved me some time.

Anyway, this is good evidence that the V6 is no slouch in it's torque delivery. Sure, it produces less net torque overall than the V8, but it delivers it beautifully from 2,000 RPM and up. It's a very flat torque curve, which is expected due partly to it's undersquare bore & stroke. For those who are not familiar with the term "undersquare", it basically means that the stroke is greater than the bore, which is good for making an engine deliver more of it's torque at lower RPM.

Just to avoid turning this thread into another flame war, I'm in no way putting down the V8. It's a great engine for sure. But I think the V8 fans need to understand the merits of the V6 before dismissing it as a high strung car engine. It's anything but that and the graphs illustrate that perfectly.

 

[Mike07SE]

Nice find and useful info.
Would be very interested in seeing curve #'s for the VVT-i V8.

 

[progress4m]

Great info thanks!

...

NOTE: in 2006, Toyota added VVTi to the 4.7L V8 engine...unfortunately, i do not have the torque curve for that engine. I am sure that VVTi would improve the 4.7L V8 engine torque curve at higher rpms, thus making it as flat as the V6's curve.

Small correction VVT-I for V8 was introduced in 2005 not 2006.

 

[Thai]

Great info thanks!
Small correction VVT-I for V8 was introduced in 2005 not 2006.

Oooppps...thanks. I edited my post with the correction.

 

[SpaceNeedle]

-Both are great options

-V8 sounds much better esp with exhaust, feels smoother

-Gas mileage benefits of the V6 a wash for me

-V6 does not require a timing belt change, but $1K is nothing for a job that's done every 90K miles?

Conclusion: Cool analysis and I'll take the V8 everytime.

P.S. In the V8 PDF, it says premium unleaded recommended? True?

 

[Mike07SE]

No, I don't know many that do. My buddy doesn't in his 8.

 

[ToyTech99]

P.S. In the V8 PDF, it says premium unleaded recommended? True?

Toyota seems to flip-flop with the octane recommendations/requirements over the years.

The V6 has been virtually unchanged from '03 to '09, but in the beginning they recommended 91 octane fuel for the V6. Now they say 87 octane is recommended in their literature. Go figure.

 

[paraordnance]

wow, its nice to know that V8 at 1000 rpm have same torque as V6 at max :dancin:

 

[SpaceNeedle]

Toyota seems to flip-flop with the octane recommendations/requirements over the years.

The V6 has been virtually unchanged from '03 to '09, but in the beginning they recommended 91 octane fuel for the V6. Now they say 87 octane is recommended in their literature. Go figure.

Perhaps it has to do with the rise in gas prices?

That'd be my best guess. I'm going to try fueling up with premium and see how it goes. I've always done regular unleaded in my V8.

 

[ToyTech99]

wow, its nice to know that V8 at 1000 rpm have same torque as V6 at max :dancin:

Yup, just about. But it's also good to know that the V6 produces more torque than the V8 as the RPM's cross over into the 5000 RPM range. That's astounding to me, considering how much more torque the V8 produces. I wouldn't think the V6 would out-torque the V8 at any RPM.

 

[Thai]

Yup, just about. But it's also good to know that the V6 produces more torque than the V8 as the RPM's cross over into the 5000 RPM range. That's astounding to me, considering how much more torque the V8 produces. I wouldn't think the V6 would out-torque the V8 at any RPM.

Yup...old school (V8 dates back to LS400 engine) vs. new school (VVTi).

 

[SpaceNeedle]

Yup, just about. But it's also good to know that the V6 produces more torque than the V8 as the RPM's cross over into the 5000 RPM range. That's astounding to me, considering how much more torque the V8 produces. I wouldn't think the V6 would out-torque the V8 at any RPM.

But I rarely if ever go anywhere near 5000RPMs in my 4Runner. Even in my sports car I don't venture up that high on a regular basis.

 

[Thai]

But I rarely if ever go anywhere near 5000RPMs in my 4Runner. Even in my sports car I don't venture up that high on a regular basis.

True for me...the few times that i have gone up that high in my G500, i had tears running down my face as i look at my fuel gauge....

 

[ToyTech99]

But I rarely if ever go anywhere near 5000RPMs in my 4Runner. Even in my sports car I don't venture up that high on a regular basis.

Yeah, that's because the torque drops off drastically in the V8, so why bother messing around at that RPM. I have a V6 and my 4Runner regularly sees 5,000 RPM. It keeps pulling hard up there, so why not?

That's the whole point of power and torque curves. It's good to know that the V6 keeps on pulling throughout the entire rev range. It's a nice, flat torque curve.

 

[paraordnance]

I dont think I ever cross 3000 rpm mark (up to 2000 rpm for the most part) so I'm driving right in a sweet spot :hungry:

 

[ToyTech99]

I dont think I ever cross 3000 rpm mark (up to 2000 rpm for the most part) so I'm driving right in a sweet spot :hungry:

Damn, you guys must drive like old ladies! :lol:

Don't you ever merge on to a freeway, or blast away through a toll booth? Hit that skinny pedal a little and live it up. I guess it's just weird to me that anyone would buy a V8 and keep it under 3000 RPM!

I've had several V8 Mustangs in my past and they all regularly saw the entire RPM range. The older 5.0L engines would really start to drop off after 5000 RPM, but the newer 4.6L Mustang engines keep on pulling right to the redline. They are all a blast to drive and I'd drive them that way. I'm a closet Mustang freak, in case you were wondering.

 

[paraordnance]

Damn, you guys must drive like old ladies! :lol:

Don't you ever merge on to a freeway, or blast away through a toll booth? Hit that skinny pedal a little and live it up. I guess it's just weird to me that anyone would buy a V8 and keep it under 3000 RPM!

I've had several V8 Mustangs in my past and they all regularly saw the entire RPM range. The older 5.0L engines would really start to drop off after 5000 RPM, but the newer 4.6L Mustang engines keep on pulling right to the redline. They are all a blast to drive and I'd drive them that way. I'm a closet Mustang freak, in case you were wondering.

if I punch it, my mpg suffers badly never had a need to drive like crazy, I have a Kawa ZX-10R to do just that . Now thats when you get a blast, after the Z, 4Runner does not provokes for sprints rather for slow and easy cruizin :nono:

 

[ToyTech99]

Yeah, I do most of my driving "slow and easy", but I still need to open her up every once in a while, gas mileage be damned. I can't possibly drive easy for very long, even when I'm behind the wheel of my 4Runner. I guess I'm just a bit of a lead foot.

 

[BlairB]

if I punch it, my mpg suffers badly never had a need to drive like crazy, I have a Kawa ZX-10R to do just that . Now thats when you get a blast, after the Z, 4Runner does not provokes for sprints rather for slow and easy cruizin :nono:

So if you are not concerned with aggressive driving and more with the mpg why are you so happy with the V8's torque band :lmao:

In all seriousness though, I have had both a V8 and V6 4runner and love both engines. The V8 does have a little more power, but the V6 is more than sufficient. It has never held me back once and I wheel with guys with V8's regularly.