Yes, lag is a word just as "you're in the wrong gear" are all words. Lag is used to describe the delay you get in power applied when you put your foot on the throttle. For a normally aspirated or supercharged petrol with the increase in wheel torque is as near instantaneous as makes no difference. For a turbocharged engine running above the boost threshold, there is a perceivable delay when you open the throttle to when you get a significant increase in wheel torque. This is lag.

You seem to be simply referring to running in too high a gear to give the required acceleration; dropping a gear in a manual (the very thought of this seems to cause diesel owners nightmares), or depressing the throttle hard enough to cause an auto box to kickdown will fix the problem.

Dont be silly.

That makes the experts who decided the prize silly then?

I find turbo petrols are the perfect compramise... Low down grunt of a diesel but with a decent useable rev range.

My old Saab did 100mph in 3rd gear, made 390lbft at 2.5k and held 300hp from 4000 to 6000 revs.. You could plant it in 3rd at 40mph and the acceleration was relentless till the limiter. It'd take a very impressive diesel to make useable power for such a huge range.

Saying that as super-effective as it was, it was so boring. so was my Megane F1 before it 260hp/300lbft... So now I've bought (out of choice!!) a very revvy 2.0 N/A Clio 197. It lacks the grunt yeah but it's a stack more fun and I'm a lot less likely to get in trouble with the law.

It's more than fast enough in every day driving just keeping it below 4k... You dont need any more power! A 1.2 would be adequate from A to B.

If I need a bit more go to over take I'll change down or on a short slip road I'll rev it out to the limiter. No issue.

I am fortunate in that i get to spend a lot of time in car-friendly, cheap-fuel, many empty-roads central/southern California and have done, since late 1981.
A good friend in Santa Barbara is a multi-millionaire and as keen on cars and motorcycles as i am, so his huge spending power allows him to have a garage of cars 99.9% of us here can only dream about. (Current garage includes an 1,100 bhp bi-turbo 2009 8.4 litre Dodge/Chrysler Viper and a 2011 McLaren and a 300+ bhp motorcycle).
The worst 'lag' i ever witnessed in a supercar was his vastly over-rated Ferrari F40, which he had for 2 years quite recently. It was actually the most over-rated car i have ever driven, in every way just about. When you first pulled away, you got the feeling that it might just be the perfect engine, then it went into a hole the size of the Grand Canyon until the turbos finally spooled up fully, whereby there was an almighty OMFG shove in the back and you needed to get the gearchanges just right, or the power fell away as if someone had cut the igniton completely. Horrendous engine for something which is supposed to be an all-time great. Something like the engine in his S65 AMG was just sooooo much better.
Incidentally, the cabin was also appalling, the body panel fit was as if the thing had been knocked up in someone's double garage with a car kit which arrived by post and generally the engine and car felt like something would break at any moment.
Now that DID have LAG!

Sorry, but although the mpgs and power are very good, I find the evo engine more impressive that it can develop 400bhp from 2.0, pretty good for a mass production engine.

1. The turbo isn't that big on the evo X 400
2. Although its not a massive challenge to get power through forced induction, I think it's a good effort for a full production engine.
3. Agree regarding Honda, was just replying to the comparison of the 123d engine to the evo engine.

Yeah exactly, as you say much power can be extracted using turbos, but making it reliable with a warranty at that power is a pretty good effort.

I think we're probably going to struggle to agree.

For me a lot comes down to the sort of car you're driving. Recently I drove the new twin-turbo Audi V6 diesel in an A6. Wonderful engine, suited the car perfectly. Drove the 3.0 turbo petrol F10 5 Series on the same day and concluded that for that sort of car, the diesel probably edges it these days (that said, the Audi A6 with supercharged V6 is rather lovely).

On the other hand, in small sports coupe like a 123d I far prefer the zingy power delivery of a nice NA petrol lump, especially a straight six. I don't find the 23d remotely exciting or engaging. It's impressive, effective, and other words like that. But remotely soul stirring it ain't. And that's a complete deal breaker in a driver's car, for me.

In a nutshell.