Viewing 40 posts - 41 through 80 (of 139 total)
  • Diesel turbo lag?
  • smiffy
    Full Member

    get one with a little tubo inside the big turbo. my last two have had this. the lower BHP one actually drove better, the one with the bigger big turbo had two noticeable platea, whereas the other was steady from 1500 all the way

    tron
    Free Member

    get one with a little tubo inside the big turbo

    Really? That'd be a miracle of engineering 😆

    There are plenty of variable geometry turbos, sequential & twin turbos, but one inside another?

    Surf-Mat
    Free Member

    Tron – the chicken and egg turbo maybe?

    Conor – that petrol unit is one if the dullest, harshest sounding units ever made. It's also pants on fuel for its power output. Not one of VWs finest.

    Their equivalent diesels were a bit agricultural but far better.

    samuri
    Free Member

    I find some of the comments above very odd but each to their own. Personally I hate driving petrol cars because you have to scream the nuts off them to get them moving.
    I can't imagine why anyone would scream a diesel, it's a complete waste of time. Keep the revs between 2 and 3 thousand and it'll move just fine.

    Surf-Mat
    Free Member

    Mine redlines to 5k in every gear in sport box mode. Doesn't seem all that pointless. The nicest engines are big capacity non turbo petrol. Shame they are so terrible on fuel and emissions. So the nearest thing is a big block turbo or twin turbo diesel with small sized units doing well but all sounding dreadful.

    samuri
    Free Member

    Yeah, both our diesels will redline but since all the power is generated much further down it seems like a waste of effort keeping the revs high.

    Spongebob
    Free Member

    There is no detectable lag whatsoever on any of the 1.9tdi VAG engines i've driven over the past 14 years. I am amazed how quick they are to respond infact. Much quicker than any petrol engined car i've had!

    missingfrontallobe
    Free Member

    Might not be turbo lag, 200 miles means the engine is still quite tight, won't be run in until closer to 10,000 miles or so.

    Surf-Mat
    Free Member

    Samurai – torque or power? Torque should be fairly flat at all revs, power will rise and dip just before the redlines on mist diesels. On my Astra diesel happened under 2.5k or over 4.25k. The two turbo on the current diesel make it interesting from almost idle to near redline. Much more useable.

    JonEdwards
    Free Member

    BMW 320D here too. Plant your foot and it pulls like a train from 1800 all the way to 4500. It's also geared tall enough that I'm not having to change gear constantly. 3rd is good for 25 through to 75, 80 ish if I'm feeling like a hooligan. Relatively small, VGT turbo. There is a bit of lag bel0w 1800, but easy enough to drive round it.

    I test drove a Jag X-type 2.2d. That had a very narrow power band. Daftly quick for a very short time, nothing, change up, repeat. My old passat 1.9 110 had a fair bit of low down grunt, but died after about 3k. Petrols? Great if somebody else if paying the fuel bill…

    Oh, and for the guy who wanted a more comfortable ride – Koni FSD dampers are supposed to be good. Might be bunging some on the beemer for similar reasons. As far as I can work out, they're shimmed, so speed sensitive like a bike shock, rather than cheapo port/orifice style.

    tonyg2003
    Full Member

    It might be that the engine is tight or it has a problem. Renault engines are particularly noted for turbo lag. Maybe it's just your expectations, Laguna's diesels aren't exactly a ball of fire? It's a fairly big adjustment after a Civic typeR!

    Sequential twin turbo diesels (saab, bmw, VAG, merc, volvo etc..) and something with a few more cc should feel fairly free of lag with a bigger spread of torque (up to 2000rpm band) and more power at hire revs. Get yourself a better hire car if you can!

    oink
    Free Member

    my vito 120 (3.0 V6) is a rocket ship, never noticed any lag, but with over 200bhp it's not short of power

    Surf-Mat
    Free Member

    What most people are describing isn't lag, its just the bit before the turbo kicks in. Modern turbos spin up quickly unlike older ones found in petrol cars of the 80s and before.

    The only problem with the big torque of decent diesels is tyre wear. I've had 8k miles from my rears and they are nearly worn. Yikes! Fun though.

    chickenman
    Full Member

    My 130bhp Passat (had it 9 years) has always been great for nipping past "Bunnets" heading down to Peebles on a Sunday: In 4th at say 40mph it pulls like a train, no turbo lag at all! Plus it will do about 60mpg for the trip.

    iainc
    Full Member

    surf-Mat – dunno if the tyre wear is down to the torque if you have the traction control on most of the time ? my measely 318d is nearly through it's original rears with under 11K miles and it's got chuff all torque vs a 330..

    ..or do you switch off that button on the dash 😆

    samuri
    Free Member

    Torque I guess, I must be getting to be a right old man that I prefer something that just pulls steadily in top gear. 😉
    Like the comment above though, in third my Honda will go from 25 right the way up to 80 odd with no discernable alteration in acceleration. Our audi needs a bit more work to keep it moving along admittedly but then it is a bit quicker.
    'Like a train' is an expression made for big engined turbo diesels.

    Surf-Mat
    Free Member

    Iain – that's a bit of a pain! Getting mine laser aligned when I replace the tyres just to make sure they are okay. Our cars have a lot of negative camber on the rears to help handling but it also means extra inner edge tyre wear. I thought mine was made worse by the pokier 335d engine but maybe not?!

    Reckon the hire car is just a crap one. Renault aren't very good at diesels. Or building cars that don't fall to bits!

    br
    Free Member

    To whoever commented about French cars been crap, was not diving when diesels started to become more popular – the 1.9TD's in the PSA range were streets ahead of practically any other diesel engine supplied in cars, plus they had a 1500-4000rpm range.

    My BMW 320d drives just like a petrol engine (except with more torque) up to its maximum revs which from memory are about 4000 rpm.

    Got to disagree, in my friends 530d you can always 'feel' the diesel 'clatter', especially compared to my petrol 5 series – and the beauty of a (normally aspirated) petrol engine is that it has a good rev range, with no holes – practically 500-6000+rpm.

    I'm not convinced on economy either, especially in bigger engined cars – gains of 5 mpg for me just aren't worth spending the extra – nor having to put up with the extra noise/vibration/service costs.

    stilltortoise
    Free Member

    Got a Civic 2.2CDTI, not problems with lag here

    lucky you. I've had a Volvo S40 (naff), Laguna, Octavia and Mondeo before my current Civic. The Civic has the worst turbo lag of the lot (except the S40 which never did anything!) because it is so unpredictable. I have owned it well over a year and I still haven't learnt how to find the sweet spot 100% of the time. It spoils an otherwise excellent car whose sweet spot is worth finding.

    Surf-Mat
    Free Member

    Br – nonsense in many cases. My 335d is way quieter than the 335i which is a very close petrol comparison. An extra 5mpg? Make that at least 15 more. All with a much cleaner pair of exhausts thanks to a dpf.

    Apart from firing up, there is no clatter. Your mates 530d must be an old version. They have moved on heaps.

    Renault may have moved diesels on a bit but at the moment they aren't very good.

    br
    Free Member

    My 335d is way quieter than the 335i which is a very close petrol comparison. An extra 5mpg? Make that at least 15 more.

    Yeah, right…

    http://www.tyresmoke.net/forum/bmw-5-6-7-series/84539-535d-mpg.html

    They are reporting 25-30mpg for a 535d whereas my 535i averages 20-25mpg.

    iainc
    Full Member

    Surf-Mat – aye, quite surprised at the wear, but then again I do like to push it along, especially as it's a company car so I'm not paying for the tyres. 😛 .I have altered my opinion a bit as I have got used to the car….for the better TBH. Ok it's a bit small compared to proper estates, but the quality is pretty good (at least compared to the wife's C-Max and previous cars) and it's fun to drive – the road holding is, and I am now convinced, better than the MK 5 Golf GTi that it replaced – this I think is all down to the balance of RWD. However, another 3 months and ice and snow here is Glasgow and it's gonna be pish 😆

    samuri
    Free Member

    http://www.tyresmoke.net/forum/bmw-5-6-7-series/84539-535d-mpg.html

    They are reporting 25-30mpg for a 535d whereas my 535i averages 20-25mpg.

    I have no idea what those guys are doing but we (4 blokes) shared a 535d down to London a couple of years ago and for the (admittedly) mostly motorway trip, it was in the mid 40's mpg, and that was going off what we put in the tank when we got back home.

    ziggy
    Free Member

    Speaking of mpg, so far only 33 average, not good, although it is a hire car 😉

    coffeeking
    Free Member

    Are we sure we're talking turbo lag in the first post, not the point below which the turbo won't spool to produce positive pressure? There's a difference, one is almost unavoidable, the other is dependant on designers turbo choice, mapping, variable geometry etc.

    M6TTF
    Free Member

    All very interesting for me as looking to change my passat soon. Currently in a 1.8T petrol, thinking about diesel but have a lot of the prejudices most people have: sound like a taxi, eat tyres if you drive with a bit of spirit, belch out clouds under acceleration and constant gear changing. That said a friend just got an x5 3.0d sport. It sounds good and goes well – he's only getting late 20's on mpg though. Had a a3 2.0tdi sport for a few weeks. It had the dsg box on it too which IMO didn't suit the engine. It did take a bit of getting used to pulling out of junctions as there was a definite nothing then a big shove as you set off. Seems to me that big capacity diesels are great to drive but not really much more economical than a small petrol engine, especially for my 15miles windy road commute with to schools to navigate

    tron
    Free Member

    All with a much cleaner pair of exhausts thanks to a dpf.

    You're talking rubbish. Even with a DPF, Diesels produce far more emissions that are bad for human health than petrol cars. There's generally less CO2, but more poisonous crap.

    nickf
    Free Member

    Hilarious turbo lag on an E300 tubrodiesel I used to have. Put your foot down at a standstill, hear the whistle as the turbo spun up, sadly without any accompanying movement.

    About two, maybe three seconds later, the car would pick itself up and hurl itself down the road. Very frustrating at first, but you quickly learned to drive round it.

    Loved that car.

    HoratioHufnagel
    Free Member

    my experience of diesels is that the MPG advantage narrows a lot when you're giving them some stick, but drive more efficiently and the opens up again.

    The more powerful is is, the more difficult it is to drive efficiently however!

    Everywhen
    Free Member

    2.0 160 Insignia CDTI 6 sp Auto.
    No lag, getting smoother and faster as the miles increase.

    I find the low rev torque of modern diesels must more suited to modern driving/getting older.

    stumpy01
    Full Member

    As mentioned above, the 'turbo lag' being described probably isn't turbo lag, but just the region where the turbo isn't actually spooled up & doing anything.

    My Ibiza won't really accelerate in that region, but will pull along if maintaining a steady speed. It starts to pull decently at about 1500rpm and really goes from 1800rpm onwards. It will then accelerate hard up to just over 4k revs where it starts to tail off by 4.5k revs.

    Whenever I have been in a car with someone who describes their diesel as 'nothing, then a massive shove in the back' seem to just stick their foot to the floor below the point where the turbo comes in, then keep it planted as the turbo spools up. There is no modulation of the throttle and no matching of driving technique to the engine characteristics. It can't be particularly good for the clutch.

    I get at least 22,000 miles out of a set of front tyres and the last tank averaged out at 58.5mpg.

    Splash-man
    Free Member

    I reckon a certain amount of this must be down to the new engine.

    My experiences of teh VAG 140PS engine has been great. OK, its a little slow off the line to start but then get it above 1500rpm and everything is great. As for constantly changing gears – I find on the open road I often only use 3 – 4 of the 6 when accellerating up to speed. I find the ratios are very close and double shifting works just fine.
    Getting 25 – 30k out of a set of tyres is great…
    Somebody mentioned service costs – are diesels really more to service nowadays ? OK the longlife oil isn't cheap when you only have to change it every 20k miles it doesn't exactly burn a hole in your pocket.

    Surf-Mat
    Free Member

    Splash – pretty sure diesels aren't any more to service and as you say, intervals are now huge. Certainly not complaining about my 335d servicing costs to date.

    tron
    Free Member

    Somebody mentioned service costs – are diesels really more to service nowadays ?

    There are normally more jobs on the service schedule for the diesel than the petrol. I'd be surprised if that didn't make it pricier, if done properly. But most services consist of an oil and filter change, some paper mats and a bit of grease on the door hinges 😆

    Macavity
    Free Member

    The OP might have a point about the newer 6 speed gear boxes. But the engine is unlikely to be at fault.

    Surf-Mat
    Free Member

    I reckon you need six speeds to keep "in the zone" when needed.

    When I got my Astra (new at the time 1.9CDTi 150) I HATED the power delivery for a while – the previous car I was forced to sell due to vandalism was a Golf R32 which a lovely power band. The Astra did nothing until 2500rpm, went a bit mad then ended just over 4000rpm. Compare that to a car that had seamless delivery from idling to almost 7000rpm!

    But I soon learned to drive "around" the power delivery and found that if you knew how to get the best out of it, it really was rather quick.

    Now the BM does the changing for you (6 speed ZF auto) so you don't have to think and I'd say 95% of the time it gets it right. But once in a while there is a hesitation or slightly jerky up/downchange which can be annoying.

    In terms of the engine though – hard to fault. Massive pull from almost idling to daft speeds. I still laugh out loud sometimes when I floor it and get flung at the horizon.

    But back to the OP – engine not run in. It won't be lag in a car that new – that's old school turbo stuff.

    Turbos hardly lag now – I tested an Evo FQ360 (366bhp 2.0 litre 4 pot) a while back – if any car is going to have lag it's this one. But there was almost nothing. Turbos have moved on a long way.

    FunkyDunc
    Free Member

    I've always had petrol engines until the last year and now have a Ford 2.0 TDCI 130bhp and a VAG 2.0 140bhp. Between the 2 the VAG has a slightly better power delivery (smoother through the rev range) but it comes in in more of a rush and tails off quicker the the Ford, and is no where near as quiet.

    I was surprised on getting both at how many gear changes you need to make either 1. to go quickly or 2. To drive an maintain mpg, in that way I think they are more of a pain to drive than petrol.

    Both are also difficult to maintain momentum in if knocking on a bit through corners, you have to second guess when to apply the throttle in order to get out of the corner quickley (ie before the apex).

    Diesels great for mpg if you drive slowly, crap with if you want performance! (although not driven a BM 330d which are supposed to be better)

    Best turbo car I ever had was a Suzuki Cappuccino. 650cc with a lump of a turbo on it, it fair shift and nearly no turbo lag what so ever.

    molgrips
    Free Member

    I have no problems with turbo lag on manual VAG cars. All you need to do when pulling away is let the revs go up a bit more. It's really not that hard to get the hang of. Took me a few drives, that's all.

    I dunno what you are talking about re gear changes either. My old car was a Seat Ibiza TDi – same power and 0-60 times as my dad's Fiesta. When I drove his car, I was change gear all the flippin time. You'd go into a corner and have to select third to get out of it. In my diesel, you could stay in 5th and still be quicker out of the corner. Really no idea what you are talking about.

    The power band is smaller if you look at the numbers on the rev counter, but there's no need to do this. Just put some tape over the numbers 1-5 and put 1-7 on instead, and you'll not notice a thing. The gears are higher, which makes the power band go further. As Mat says, you just need to un-learn all your petrol driving habits and re-learn some diesel ones. Like don't red line it all over the place if you want to go fast, and keep the turbo spooled up.

    I'm trying to compare like with like – ie same power. Some people on here compare 3.0l V6 petrols with 2.0 TDis – no comparison, in price or running costs.

    molgrips
    Free Member

    someone who describes their diesel as 'nothing, then a massive shove in the back'

    One of the first really widespread diesel engines was the VAG PD engine in 1.9 form. This did have a much narrower powerband than more modern efforts. My Ibiza had this, and you had to change up at about 3.5krpm to proceed most rapidly. NOT at the red line.

    I think the reason for the massive discrepancy between the Fiest and the Ibiza was that in the petrol Fiesta, the rev range for comfortable quiet reasonable driving was in a different place to the rev range for rapid progress. In the diesel Ibiza both rev bands were the same. So if you were used to razzing your petrol car around at high revs, you'd hate the diesel. But if you cruise around in a relaxed way then the diesel was far better to drove. And ultimately both cars were the exact same power and speed. But the diesel also went 50% on the same amount of fuel 🙂

    Surf-Mat
    Free Member

    Diesels great for mpg if you drive slowly, crap with if you want performance! (although not driven a BM 330d which are supposed to be better)

    Or a 335d which is a fair whack quicker still 😉

    Diesels have now shed the "slow" moniker. Even a 140TDI VAG unit is nippy, a 170TDI even quicker. Then you get to larger capacities and/or twin turbos and things go a bit mad. A 123d is very rapid. So is any Merc with a 250CDI engine. Then you step up to the 6 pots like the 3.0TDI unit used by Audi. Then BMs variants (and Jags new bi-turbo) are even quicker. Then upping the price by many pounds there are some very powerful V8 diesels. Sadly only found in very heavy cars so far. Then top end of the mad scale is the Audi Q7 V12TDi with utterly demented power and torque – 493bhp and 738lbs-ft.

    Even at the bottom end of the scale, diesels are often nippier due to easy torque and lazy power.

Viewing 40 posts - 41 through 80 (of 139 total)

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