Why are most petrol V6 engines so terrible? | Auto Expert John Cadogan

OLIGHT DISCOUNT! (These are awesome.)
12% off: Use code AEJC

AutoExpert discount roadside assistance package:

[FG-fkjb]

I will take that old, tried and true naturally aspirated, over engineered 3.5 l V6 engine (like Toyota 2GR-FE for example) with its port injection, bulletproof reliability, smoothness and quietness over all those tiny but loud turbocharged direct injection engines with their carbon deposits and oil consumption any time.

[ChrisRobato]

Having lived decades with inline 4s and V6s, I would prefer a V6 with displacement any day any time in terms of smoothness and the curve of power delivery over the current trend of turboing lawnmower engines.

[christopherhamilton]

I have a 3.5 VQ engine in my 2002 Maxima. Has been a great engine. Still amazes me with how much power it has. It’s not bad down low, but it does love to rev to really get down the road! 180, 000 miles… paint is shot, leather is torn, no modern gizmos… but I love it!

[milo]

I own a 2010 Kluger KX-S (3.5 V6 - 9.2 BMEP) and a 2010 Mercedes E250 CGI (1.8 I4 Turbo - 15.2 BMEP) and I now which one will last longer. I am all for advancements in technology, but complexity just brings problems. Kluger does without high pressure fuel pump, turbo, direct injectors etc and does the job perfectly fine without any strain. If I wanted to, I could use E10 in Kluger, but E250 requires premuim petrol. Keep it simple and reliable. The Toyota recipe!

[svenomick]

That is why the Barra engine is so good straight 6 way to go.

[boogitybear]

The 3.8 V6 Series 2 GM used to make were indestructible. Sadly, they changed to something worse.

[buddybestor]

Port injection engines are so much quieter than direct injected. I have a 2011 Mercedes V6 M272 engine and when Mercedes upgrated to direct injection it did bump up the HP from 268 to 302. However they lost thir quietness and in addtion....port injection can keep the valves cleaner longer. Both have plus and minuses.

[majorlaff]

My 2006 Toyota Kluger is emphatically GOOD. Okay, it's only got 150, 000kms but it's only let me down once - alternator. It has loads of acceleration, carries seven (five adults, plus two littlies in the dickie seat), has air-con like a fridge, runs quiet as a Rolls, holds the road due to constant 4WD, and is just a comfy, well-made car. Bought in 2008 with only 30, 000 kms, it is by far the longest I have ever had a car. Previous cars for a few months to two years. If the engine blows up or transmission explodes, I'll get something else. Until then, happy Klugering for me.

[Alaster-]

Can't agree John. Having limited experience compared to many, I've driven a few enough to know that turbo 4's suck. My driving style is mostly gentle without being tardy, with few accelerator excursions past 1/2 throttle.

Experiencing mostly the I4T in BMW 330i & Mazda CX-5 2.5T, but several loan cars of the small sedan/hatch nature. Most have trick new transmissions and go like stink, relatively, when pushed hard.

But none of those engine are as nice drive as V6 mitsi 6g74 3.5, , the 3.5 V6 200kW Toyota rav4 or the newer VQ35 V6 on the Pathfinder r52 (which we own currently - yes, it ticked more boxes than anything else). These engines are more responsive at low revs and throttle input, seem to pull easily without surging at low throttle inputs, and with all these I can match or better the rated fuel economy. I can't get within +1L/100 of the turbos, and generally much worse. But it's the turbo spooling up and down on light throttle that is most annoying. Try to maintain a speed up a hill that requires a bit more throttle, then the turbo spools up and next you're doing 20 over with no additional input. Drop the throttle a little to compensate, and your 10km under again...

The turbo fuel economy is a fallacy. When pushed normally, they use easily as much as NA cars. I'm convinced most of the fuel economy bonuses are coming from the trick new gearboxes that are lightyears ahead of a decade or so ago. Stick a spanking new 8sp/10sp behind an "old" V6 and I'm betting real world tests would lean to V6 way compared to I4T.

[clover]

Toyota's 1GR and 2GR and Honda's J35 engines are all legendary.

[dekkerlundquist]

Hi John, thanks for another great video - very helpful and interesting, but you didn't mention reliability. Aren't the older V6 designs generally going to have better reliability/longevity than more modern 4 cylinder engines which have turbos generating more pressure and heat etc?

[stevengriffin]

Blah blah V6 compact, punchy, reasonable economy, maintained and used properly.A good design is the key, some are good some aren't, forget all the techno babble this guy endlessly spouts.

[tareskisloki]

I'm on my third Toyota V6, I used to think of them the same way as Remy, having started with the 3VZ-FE, then moving to the 5VZ-FE, they really needed to be worked to give their best. I assumed it was just the way V6's were. However, I now have the 1GR-FE, and it has a brilliant torque curve, coming in at low revs and staying almost flat through the whole rev range.

[archygrey]

V6's never made much sense to me compared to I6's, an inline six has half the heads, camshafts and exhaust manifolds and is inherently balanced as an engine and far easier to work on, the only advantage i can think of for v6's is that they can fit better in fwd cars and may be a bit lighter.

[Tesla.tricks]

Hi John, always a big fan of your videos . Just a tiny comment regarding Mazdas 2.5T 4cyl, (I own one). It’s 170kw with 91, and 186kw with 95/98octane. Been driving it for nearly six years and the torque is always enough for such a big car (cx9). So this engine is all about low end torque vs power that like u mentioned no one bothers reviving.

[timhancock]

As long as you changed the cambelt and tensioners regularly the Alfa V6 Busso was rock solid, rarely suffering from crank failure or head gasket failure. 2.5 V6s always lack torque but at 3 or 3.2 litres the Alfa V6 was excellent. The 12 valve was arguably the nicer drive, but the 24 Valve was superb between 4500 and 6500 rpm, and just wanted more throttle no matter how hard you drove it. There has been nothing quite like it unless you buy a supercar.

[hughsavage]

Well, there's a shock. Turbo engines outperform normally aspirated. Agree they burn brighter but certainly don't last longer. My new RX350 pulls very well from low revs. In fact not far off the Turbo Diesel Euro motor I replaced it with. The Lexus does like to rev but power delivery is strong all the way up the rev range. I will still buy a normally aspirated V6 over a tinnie Turbo any day. It will still be running in 200k unlike most Euro Turbo powered crap.

[tbone]

My 2.0 turbo wrx was great for top end power but I hated the turbo lag and it guzzled premium. My 3.5 V6 Camry lacked just a little bit at the low end and almost used as much fuel as a V8. Last 5 years I've been driving a V8 Holden Calais wagon with direct injection LPG. Absolutely love the corvette sound when exhaust valves are open and a rear wheel drive V8 is just a lot of fun. It's a torque monster, can tow a mountain, rips away from others at the lights without even going over 2000rpm, top end puts out 300KW and I still use around 10 litres per 100Km like the Camry on highways but LPG is 1/2 the price of petrol. I love how LPG burns so clean, the oil looks fresh even at 15, 000KM service intervals. One more thing, this car has almost double in value since I bought it, feels good driving an appreciating asset.

[Crunchifyable]

In actual daily driving I tend to find 4 cylinders to be high reving and loud. Whereas my cars, v6s, drive in the low end of their RPM range and don't have the noise / vibration that I'd get with a flat 4 for whatever reason.

So I really hope I can get another v6 in 10 years. If I can't maybe I'll look for a v8.

[darrelladrian]

Hey John I'm sure everything you mentioned is technically dead on the money however perhaps it's one of those situations where the physics written down on paper add up perfectly but when applied to the everyday practical drivability and pleasure derived from driving the vehicle it doesn't stack up emotionally. I have a 3.5 Aurion which I bought new its got 225, 000 ks on it never missed a beat. Some years ago whilst in the UK I bought a new Audi A4 1.8 turbo sport. At the time it was the most refined and fulfilling car I had ever owned, but no word of a lie the Aurion gives me more driving pleasure. I am a very reasonable driver, not a rev head and there's just something about a large engine that feels so smooth, quiet and muscular.
I guess its a bit like comparing a Bentley with a Ferrari there just a different animal but both lovely machines.