Tumbo

For those of you that wonder:

S8 and Gallardo. How do the V10s differ?
Throwing out terms like “de-tuned”, it might sound as if Audi simply runs a lesser engine control program, or made simple changes to the S8’s V10 engine to differentiate it from the Lamborghini. However, the truth isn’t really that simple and changes are more complex for reasons you might not expect. In fact, looking more closely at the A8’s V10, it seems de-tuned is a rather inappropriate way to describe the new mill.

A closer look at the two engines shows that the S8’s V10 is hardly the lesser of the two. Some might argue it’s actually the Gallardo that’s de-tuned, with smaller displacement and without FSI. Peer over the power curves of each car though, and you’ll see it’s more a factor that the engines have been optimized for two very different vehicles: a light mid-engined sports car with higher horsepower and more of a peaked torque curve versus a heavier grand touring sedan with gobs of torque.

In the case of the S8, the stroke is identical to that of the Gallardo at 92.8mm, though the engine’s bore has been increased by 2 mm from 82.5 mm to 84.5 mm, thus increasing displacement to 5204 cc over the Gallardo’s 4961 cc. The Audi engine also uses FSI, allowing for a high compression ratio of 12.5:1 vs. the Gallardo’s 11:1.

Together these translate to a 450-hp peak at 7,000 rpm for the S8, as compared to the Lamborghini’s maximum horsepower of 500 at an even higher 7,800 rpm. When torque is compared though, the differences between the two engines become more evident. The S8 hands out 398 lb.-ft. of torque at a lowly 3500 rpm, with 90% of that on tap at just 2,300 rpm; the Gallardo by contrast must run up to 4500 rpm to muster its mere 376 lb.-ft.

Detractors of the S8 are quick to point out that the BMW M5 bests the S8’s power levels by a good 50-bhp. While that may sound significant though, the Bimmer doesn’t hit its lower peak torque of 383 lb.-ft until a heady 6100 rpm, making the power delivery more like the Gallardo’s than that of the S8. On the track, such power is nice to have, though torque tends to be the name of the game on the highway or around town in a large sedan.





Source: fourtitude.com

Yannis

Very nice article.

S8's engine is an advanced version of Gallardo's engine with FSI giving more torque at low-medium RPM. We may see that engine be used in facelifted Gallardo with an output of around 540 hp or if rumors are true Audi is already making a 5.5 lt V10 with around 550 hp for Gallardo and Audi RS6.

GTA8.5

Very informative article but whats the weight bias of this engine in the S8.
This engine might be compact but it`s not small by any means.

Mr. Chigga_Chan

Wow very interesting write-up Audhiholic

That does seem logical that the S8's V10 is geared like that, for a sporty grand turing sedan....low end torque to get the beast moving. Great info.

bum-man

Might as well call the S8 engine a diesel with that stratospheric compression.

Yannis

If you mean the weight of the engine is 220 kgr which means 20 kgr lighter than the engine of the M5.