Nissan VQ Among Crowded V-6 Field
Nissan’s 3.5L “VQ” will be among several new or improved naturally aspirated V-6s in this fall’s Ward’s 10 Best Engines competition. In this Under the Hood installment, we look at the VQ after its most significant redesign since its launch in 1995.
October 12, 2015
Say hello to our old friend, the Nissan VQ, which set a record with 14 consecutive Ward’s 10 Best Engines wins from 1995 to 2008. WardsAuto company lore says it was the buttery, free-wheeling smoothness of the original 3.0L DOHC V-6, making 190 hp, that prompted the creation of this competition to honor such excellence.
Much has changed since that engine put all other V-6s on notice. For instance, naturally aspirated V-6s have gone AWOL as automakers seem enthralled with high-output turbocharged 4-bangers, often paired with direct injection, to take the place of the grunty V-6.
This strategy only makes sense if the 4-cyl. can deliver better fuel efficiency than the 6-cyl. In some cases, a smooth, efficient, potent naturally aspirated V-6 trumps a boosted 4-banger, because turbochargers are thirsty for fuel.
Such is the case with Honda’s excellent SOHC 3.5L, having won eight 10 Best Engines trophies between 2003 and 2014, when it was capable of a whopping 28 mpg (8.4 L/100 km) during our testing.
I wrote a column last year bemoaning the waning availability of naturally aspirated 6-cyl. engines, which had been a powertrain staple in big sedans and luxury cars for many years.
Our prayers are answered, as Nissan’s redesigned VQ will face off squarely against three other significantly improved naturally aspirated V-6s – Fiat Chrysler’s 3.6L Pentastar coming in the ’16 Jeep Grand Cherokee, Toyota’s 3.5L in the new Lexus RX and Toyota Tacoma pickup and the 3.6L High-Feature mill from General Motors, now seeing duty in the ’16 Cadillac ATS.
See attached specs of Nissan’s VQ and the last 3.5L Honda V-6 that earned a trophy. The Honda engine is not eligible this year, but it remains a benchmark for refinement and performance.
A separate spec sheet will compare the VQ with the new V-6s from GM, FCA and Toyota. Curiously, of all these engines discussed, only the Cadillac 3.6L solely uses direct fuel injection. Nissan, Chrysler and Honda stick with tried-and-true port injection for cost and other reasons, while Toyota’s 3.5L powerplant employs both direct- and port fuel injection.
61% of VQ Parts Redesigned
Let’s take a peek under the hood at Nissan’s new 3.5L VQ. It’s misleading to suggest the VQ now in the redesigned ’16 Maxima is all-new. The 60-degree aluminum block is unchanged; the redline remains 6,600 rpm; displacement is identical (3,498 cc) to that in the previous-gen Maxima; and other key specs carry over, such as bore and stroke (95.5 x 81.4 mm) and compression ratio (10.6:1).
But Nissan engineers say the VQ has been enhanced like never before. There’s a fully redesigned cylinder head with new intake ports to promote better combustion, as well as an intake manifold with wider and shorter runners to improve airflow.
A stiffened oil pan reduces engine vibration and mitigates noise. Sodium-filled exhaust valves draw heat from the head through the stem to reduce combustion temperatures, which is said to improve fuel economy and performance.
Nissan VQ V-6 now rated at 300 hp while torque remains unchanged at 261 lb.-ft.
In total, 61% of the VQ’s parts are all-new, although the double-tipped iridium spark plugs carry over. The revised engine adds 10 ponies to the 290 hp peak in the previous Maxima, but the torque rating is unchanged, 261 lb.-ft. (354 Nm) at 4,400 rpm.
However, Nissan says the ’16 VQ consistently produces more torque at low- and midrange engine speeds. Stellar midrange throttle response has been the VQ’s calling card from the beginning.
The refreshed VQ also has low-tension crankshaft oil seals, new anodized piston surfaces and new piston rings with a diamond-like coating to withstand higher temperatures.
The powertrain team focused heavily on the heads, redesigning the exhaust camshaft and adding intermediate locking variable timing (VTC) on the intake camshaft. The previous engine used it only on the exhaust side.
Perhaps the most dramatic improvement comes in the EPA fuel-economy ratings. The Maxima’s previous numbers were 19/26 mpg (12.3-9.0 L/100 km) city/highway.
Stacking up Nissan’s “new” VQ against Honda’s somewhat dated 3.5L V-6, it is surprising that Honda wins the fuel-economy challenge with a 34 mpg (6.9 L/100 km) highway rating, thanks to its use of VCM cylinder deactivation. That’s 4 mpg (1.7 km/L) better than the VQ.
Nissan doesn’t use cylinder deactivation but manages to top Honda with a 22 mpg (10.6 L/100 km) city rating from the EPA.
As we drive the Maxima, we will pay attention to its acceleration from a standstill and how it sounds under hard acceleration.
In general, it seems to maintain its composure in any situation, and the engine remains a vital ingredient in making the Maxima a sport sedan with a cult following. It goes hard without hesitation, and what we loved about the VQ years ago seems to carry over to this latest iteration.
No Stepping Up With CVT
One disappointment is the CVT, which does a pretty good job getting this big sedan off the mark with a sense of immediacy. But then, as the vehicle picks up speed, the transmission ratios adjust to keep the engine working as little as possible.
CVT in new Maxima proves disappointing.
Instead of the familiar steps in a conventional transmission, this CVT groans as if bored, making this powertrain a lot less engaging, even though the engine certainly is doing its job.
There are no paddles on the steering wheel, but the shift lever can be moved to the left, enabling manual rowing through phantom gears. This mode doesn’t exactly fulfill the promise of sporty “shifting.” Better to just leave it in automatic mode and get used to the CVT whine.
The CVT is intended to boost fuel economy, and it allowed the Maxima, fully loaded, to top 26 mpg (9 L/100 km) during a recent highway run to northern Michigan. That’s respectable for a big car packing 300 hp. The ’96 Maxima I owned, with the original 3.0L VQ making 190 hp, generally averaged 22 mpg (10.7 L/100 km).
The Maxima’s VQ has come a long way, but don’t forget Honda’s older 3.5L V-6 routinely delivered 28 mpg during our tests in recent years.
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