New twin turbo TDI from Audi revs convincingly past 5,000rpm
Discussion
doogz said:
I can't find the thread right now, i'll have a look again in a bit.
There were a couple of trains of thought on the ideal time to change up, one was that you're best to redline it, as you'll always make more wheel torque in the lower gear than you'd possible make in the higher gear (unless there's something seriously odd about your engine/gearing)
Another was that you're best changing half the rev difference to the next gear up, above the limiter, i.e. you make peak power at 6000rpm, and changing up will drop you circa 1000rpm (obviously that number will change depending on what the engine speed is when you go to change up) so take it to 6500, change to 5500, you'll be making a higher average power by keeping the engine operating as close to it's peak power figure as possible.
I recall the thread was decent, diagrams and all sorts. I'll have a hunt for it again later, should probably do some work just now.
Yes you are right, I remember seeing the same thing. Even if the power drops off by 10% past peak power, you will still be making much more torque at the wheels (and therefore accellerating faster) than the next higher gear at peak power (in most cars).There were a couple of trains of thought on the ideal time to change up, one was that you're best to redline it, as you'll always make more wheel torque in the lower gear than you'd possible make in the higher gear (unless there's something seriously odd about your engine/gearing)
Another was that you're best changing half the rev difference to the next gear up, above the limiter, i.e. you make peak power at 6000rpm, and changing up will drop you circa 1000rpm (obviously that number will change depending on what the engine speed is when you go to change up) so take it to 6500, change to 5500, you'll be making a higher average power by keeping the engine operating as close to it's peak power figure as possible.
I recall the thread was decent, diagrams and all sorts. I'll have a hunt for it again later, should probably do some work just now.
Ramses said:
BMWs are a bad example to use to make that point, their oil burners are . 3.0 diesel kicking 250 bhp Vs 3.0 petrol with a likewise 250bhp - aside from the fact that the Oil burner will be quicker, with diesel version will give 50% better consumption. (real world figures - i've gone from 330i to a 530d and average 39/40mpg comapred to 23/24)
With non-BMW the difference is less noticable. Last time I looked the BMW lump gets c10mpg better than the VAG equivalent. The VAG units getting so that tehy are not demonstrably better than the petrol.
You're using a lot of incorrect numbers to prove your point here, as the 3.0 litre turbo BMW petrol kicks out 316bhp now, with the dag dag at 293 iirc, and the petrol is also still quicker. As for your consumption figures, I would suggest your 330i was either broken, thrashed or an auto, as I'm getting 32mpg out of a 328i on my 40 mile commute - over 36 when the kids were off. Can't say i was hanging around either, and for reference, I borrowed a 330d when the kids were off and got 44. With non-BMW the difference is less noticable. Last time I looked the BMW lump gets c10mpg better than the VAG equivalent. The VAG units getting so that tehy are not demonstrably better than the petrol.
bodhi said:
You're using a lot of incorrect numbers to prove your point here, as the 3.0 litre turbo BMW petrol kicks out 316bhp now, with the dag dag at 293 iirc, and the petrol is also still quicker. As for your consumption figures, I would suggest your 330i was either broken, thrashed or an auto, as I'm getting 32mpg out of a 328i on my 40 mile commute - over 36 when the kids were off. Can't say i was hanging around either, and for reference, I borrowed a 330d when the kids were off and got 44.
Well if your comparing the 335i at 316bhp then you need to compare it against the 335d 306bhp.Both of these cars are auto's and generally the diesel gets 15 odd mpg more than the petrol. Both are very good though.
J4CKO said:
I am so bored of the whole Diesel thing, started in the nineties for most with Turbo Diesel Peugeot's that did 50 mpg, then the rest cottoned on and everybody went diesel, then we got the common rail uber diesels (335D mapped, etc) and they keep coming out with more and more of them, people spending 46 grand on a diesel Audi then they still do the "ner ner ne ner ner" its fast for a diesel, faster than your petrol rubbish and it does 80 mpg, FFS IT WAS 46 GRAND !
Now we have it revs high (for a diesel) to go with it, sure its great and goes like stink but its time for a diesel backlash, a fast diesel, it just like a really jazzy Orathpedic shoe.
Completely agree - and I have a diesel!Now we have it revs high (for a diesel) to go with it, sure its great and goes like stink but its time for a diesel backlash, a fast diesel, it just like a really jazzy Orathpedic shoe.
It gets worse! Top Gear magazine is running a new A7 to see if a big hatch works in the modern world. Anyway, its the 3.0 TDI (NOT twin turbo) model. Quite a few extras and the list price came in at £77k! 77 grand for an Audi, and its not even the plushest one! Ok, its a press car and its unlikely that anyone would spend that kind of money on one, but if you are financing £77k worth of car, the fuel costly a few quid a fill-up more is insignificant! Financing the interest on the car works out to be hundreds a month and if you are trying to save cash, spanking it on a new car isnt necessarily the best thing!
Impressive as the uber-diesels are - halo models only. And for gods sake, NEVER buy them brand new!!!!!
bodhi said:
You're using a lot of incorrect numbers to prove your point here, as the 3.0 litre turbo BMW petrol kicks out 316bhp now, with the dag dag at 293 iirc, and the petrol is also still quicker. As for your consumption figures, I would suggest your 330i was either broken, thrashed or an auto, as I'm getting 32mpg out of a 328i on my 40 mile commute - over 36 when the kids were off. Can't say i was hanging around either, and for reference, I borrowed a 330d when the kids were off and got 44.
The 330i isn't turbo ;-)The 330i was an auto, so is the 530d.
Ramses said:
bodhi said:
You're using a lot of incorrect numbers to prove your point here, as the 3.0 litre turbo BMW petrol kicks out 316bhp now, with the dag dag at 293 iirc, and the petrol is also still quicker. As for your consumption figures, I would suggest your 330i was either broken, thrashed or an auto, as I'm getting 32mpg out of a 328i on my 40 mile commute - over 36 when the kids were off. Can't say i was hanging around either, and for reference, I borrowed a 330d when the kids were off and got 44.
The 330i isn't turbo ;-)The 330i was an auto, so is the 530d.
Welshbeef said:
Ramses said:
bodhi said:
You're using a lot of incorrect numbers to prove your point here, as the 3.0 litre turbo BMW petrol kicks out 316bhp now, with the dag dag at 293 iirc, and the petrol is also still quicker. As for your consumption figures, I would suggest your 330i was either broken, thrashed or an auto, as I'm getting 32mpg out of a 328i on my 40 mile commute - over 36 when the kids were off. Can't say i was hanging around either, and for reference, I borrowed a 330d when the kids were off and got 44.
The 330i isn't turbo ;-)The 330i was an auto, so is the 530d.
Same thing happens with the 35i and 35d though.
frosted said:
Is the petrol model half price ?
You miss my point, there is this perception that a diesel being faster than a petrol car is some amazing feat, especially considering it's humble origins, like they punch massively above their weight, sure, they are fast but it isnt like its a budget option, for 46k you kind of expect a fair lump of performance. Then diesel bores go on about beating a 15 year old two grand Subaru Impreza off the lights such is the awesomeness of the diesel (despite being a diesel) and how peed off must the Impreza driver have been being beaten by a "Humble" (46 grand) diesel.J4CKO said:
frosted said:
Is the petrol model half price ?
You miss my point, there is this perception that a diesel being faster than a petrol car is some amazing feat, especially considering it's humble origins, like they punch massively above their weight, sure, they are fast but it isnt like its a budget option, for 46k you kind of expect a fair lump of performance. Then diesel bores go on about beating a 15 year old two grand Subaru Impreza off the lights such is the awesomeness of the diesel (despite being a diesel) and how peed off must the Impreza driver have been being beaten by a "Humble" (46 grand) diesel.I've never heard a diesel bore go on about beating a Impreza from the lights (because there are only about 2 diesels in production that can)
Codswallop said:
f
k me a lawn mower sounds better than that.J4CKO said:
You miss my point, there is this perception that a diesel being faster than a petrol car is some amazing feat, especially considering it's humble origins, like they punch massively above their weight, sure, they are fast but it isnt like its a budget option, for 46k you kind of expect a fair lump of performance. Then diesel bores go on about beating a 15 year old two grand Subaru Impreza off the lights such is the awesomeness of the diesel (despite being a diesel) and how peed off must the Impreza driver have been being beaten by a "Humble" (46 grand) diesel.
Thats a bks argumentThe direct petrol competitor to a £46k diesel will cost.....pretty much the same £46k!
Diesel Vs Petrol are now virtually equal in performance and purchase cost. The Oil burner will get 40-50% better fuel consumption but still sound s
t.Thats about it.
I have a Diesel, and I would rather have a petrol anyday (of equal standing)...but the diesel argument is gettign stronger to mean that for everyday type cars, the diesel is basically as good as a petrol equivalent - and on the law of averages, the petrol has more negatives than the diesel.
If fuel were £2 per gallon.... You wouldn't see me in an oil burner.
If fuel were £2 per gallon.... You wouldn't see me in an oil burner.
Gassing Station | General Gassing | Top of Page | What's New | My Stuff