If you change up at 4000 rpm then the revs will drop to a lower level maybe 3000 or 3500 depending on your gearbox. This week drop you into the less powerful range of the engine, by revving out to 5 or 6000 you will drop nicely into the max power band at 4000 rpm.
I can only get to about 3500 rpm in 3rd in my Astra K 1.6 turbo (147 KW) before I am doing NSL, not that I do that so often anyway.
I like that answer. Did not think of that explanation but it makes sense.
I hasten to add that my boy racer days are long past. The question was hypothetical after comparing the real world performance data for different engine options!
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Drive at a speed in the rev range that when you press the accelerator slightly the engine is responsive and when you release pressure slightly you feel a positive retardation. This will ensure that your car engine is operating at a good torque level. If you can combine this with good observation and slow down in time for hazards ahead and your driving should be a lot smoother. In addition you can you the power slightly to accelerate gently round a bend once you can see the exit.
This will vary with different engine sizes and characteristics.
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It all depends on the driving style you prefer. If you like to cut a dash, make a lot of noise, overtake whenever just possible, and annoy other drivers, get the tacho up towards the red line. If you have some interest in economy, make use of the band around the peak torque, near 2000rpm for diesel or 3000 (approx) for petrol.
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It does but to clarify the situation here are the curves for that engine.
ibb.co/2yjhFp2
Ah, well that power graph does change things. Yes, peak power is reached around 4k, but it stays pretty much flat right to 6k. So for maximum acceleration, you'd want to change gear at a point where the next one will land you somewhere just below peak torque (on the way up, not past 4k).
So what car is it?
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So what car is it?
Sorry, its a Mazda 3 2.0 Skyactiv G M Hybrid manual hatchback.
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So what car is it?
Sorry, its a Mazda 3 2.0 Skyactiv G M Hybrid manual hatchback.
I was curious because the 'PS' factor on the graph kind of suggested turbo as it was so flat, but the 'torque' reading didn't back that up.
Going purely by what i have read, that engine is not particularly pleasant to work hard, which is unfortunate given the (relatively meagre) torque output. So i'd suggest taking a more relaxed approach. If you are in a hurry, use the Mazda's excellent road manners to maintain momentum wherever possible rather than braking and then having to accelerate again.
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For optimum acceleration, change up at the red line. For optimum economy, change up at around 2000 revs.
If there isn't a red line you'll either have to look up the maximum power revs or let an automatic box do it for you in 'kickdown' mode (which just means pressing the accelerator firmly to the floor and keeping it there).
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According to the graph that engine is on near enough 3/4 peak torque at just over 2000 rpm, so for reasonably swift acceleration without driving it hard i would change up at between 3.5 and 4k rpm, for general driving there would little need to exceed 3000rpm.
It would be interesting to compare that graph with one from a 2 litre Honda VTEC to see at what revs and what difference the vtec comes into play, and how the Honda engine compares below vtec revs.
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It would be interesting to compare that graph with one from a 2 litre Honda VTEC to see at what revs and what difference the vtec comes into play, and how the Honda engine compares below vtec revs.
Here you are: ibb.co/3NYwpfD
You are right, it is interesting. Perhaps Mazda should have paid more attention to Honda's technology before developing their petrol compression engine!
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You are right, it is interesting. Perhaps Mazda should have paid more attention to Honda's technology before developing their petrol compression engine!
Not really, the few times i've driven my daughter's 2.0 litre NA Civics they seem utterly gutless unless you get up to the vtec band, and after donkeys years of Diesels mainly and 6 cylinder 3+ litre petrols i don't like having to rev engines high to make progress.
She also has a 2 litre turbocharged Civic which i have no intention of driving or even being a passenger in, need to be as agile as a chimp to clamber into those seats for one, and as for concrete springs on Northant's third world roads, no ta.
Interesting to see those graphs, seeing as you seem to be able to find these torque graphs easily, can you find one for our Forester XT please (or show me where to look?), its a 2.5 turbo made in 2008, supposedly around 227 hp, ahem, except it was discovered when the lpg conversion was being set up that the boost pressures might be a tad higher than expected so possible it was tinkered with at some point in its life.
Edited by gordonbennet on 10/01/2020 at 22:31
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Interesting to see those graphs, seeing as you seem to be able to find these torque graphs easily, can you find one for our Forester XT please (or show me where to look?), its a 2.5 turbo made in 2008, supposedly around 227 hp, ahem, except it was discovered when the lpg conversion was being set up that the boost pressures might be a tad higher than expected so possible it was tinkered with at some point in its life.
They are from an excellent French website which has an enormous collection of performance data. They also provide an English version (unfortunately still only in KPH):
www.zeperfs.com/en/
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They are from an excellent French website which has an enormous collection of performance data. They also provide an English version (unfortunately still only in KPH):
www.zeperfs.com/en/
Thankyou, i can't find a graph for the 2.5XT on there, but have bookmarked the site and will peruse when i have some time, much obliged.
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So what car is it?
Sorry, its a Mazda 3 2.0 Skyactiv G M Hybrid manual hatchback.
My (much older gen-1) Mazda 3 has the optimum gear change speeds included in the handbook. Have you checked yours? It may do, but like with many modern things these days, manuals/handbooks ain't what they used to be, if you get one at all.
As others have said, it depends upon your general driving style and what you need on the day as per each driving circumstance. If I'm tootling along (mine's a 1.6 petrol, and they aren't that much slower in normal use), I find that changing up at around 2-3k revs in normal conditions for smooth driving and decent mpg is fine.
If I need to overtake on a single carriageway road or suchlike, maybe 4k to ensure I get past quickly and back on my side of the road. I do give the car (only when fully warmed up and in a safe location though) an Italian tune-up nearer to the red line every now and then to clear the cobwebs away.
I suspect it'll be similar with yours. I presume as yours is the (mild) hybrid its a gen-4 car: how do you find it as regards the driving experience?
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So what car is it?
Sorry, its a Mazda 3 2.0 Skyactiv G M Hybrid manual hatchback.
My (much older gen-1) Mazda 3 has the optimum gear change speeds included in the handbook. Have you checked yours? It may do, but like with many modern things these days, manuals/handbooks ain't what they used to be, if you get one at all.
........
I suspect it'll be similar with yours. I presume as yours is the (mild) hybrid its a gen-4 car: how do you find it as regards the driving experience?
For the benefit of Andy and several other posters let me repeat what I said earlier in the thread: I hasten to add that my boy racer days are long past. The question [in my first post] was hypothetical after comparing the real world performance data for different engine options!
In fact with my normal driving I rarely reach 4000rpm let alone go above it. Regarding Mazda's recommendations on optimum gear change speeds, the instrument panel now tells you when the car thinks you need to change gear. Mazda is totally focussed on economy so the suggestions have absolutely no relation to maximising acceleration through the gears.
Comparing this 120 ps engine with my previous 2.0 MZR i-Stop at 150ps, acceleration during my normal (modest) driving is much the same. However, the newer engine is far more flexible and pulls far better at low revs in any gear. Going about town I consistently use at least one gear higher and sometimes two than I did before. Even then the gear shift indicator regularly suggests I am in too low a gear for too long.
Which brings us back to what kicked off this thread - the power and torque curves. Looking at those reveals that both the older 150 ps engine and the latest 2.0 X 180 ps engine generate their extra power only above 4000 rpm. Below that all three engines are remarkably similar on power so boy racers aside it is hardly surprising that most drivers will not notice much difference. Torque at lower rpm is another matter and both newer engines are much better. As noted above this gives more flexibility, allows driving in higher gears and hence results in much better mpg.
A final word before the turbo boys attack me. After 10 years with Mazda I am used to changing gear frequently and as a result have not noticed any lack of torque. Drivers used to small turbo engines may be less easily satisfied.
Edited by misar on 10/01/2020 at 22:15
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My comments/advice weren't for the 'boy racer', but normal driving - I mean, why would you overtake someone on a one lane-each-way road sedately? I test drove the gen-3 Mazda3 with the standard 120PS 2.0 petrol engine, and found it be not be that much different from my old 1.6.
To get the full benefit (max torque) from the car, I essentially needed to almost floor it, which is essentially what I'd have to do on my current car (not that I want or need to do that very often).
The non SA-X version in the gen-4 car (still 120PS) is a variation on that in the gen-3 car and is actually slower to 60 (by some margin) as well (just look it up in the Car by Car Reviews section). Whether that's borne out in the real world is another matter.
Besides, 4k revs isn't that high. I think my car's VVT system kicks in around the 5k revs range. My car's red line is at 6.5k revs (though continues to 8k, not that I've ever got it to go that high).
I agree that the newer Mazdas (since the split from Ford), sans MX-5, have all been designed for fuel economy rather than a 'spirited drive', even the higher-powered 163PS 2.0 petrol engine in the 3, CX-5 and 6 Sport models.
I personally think that's a shame, at least not having any properly sporty models for their 'standard' cars available in the UK. The 2.5 SA-G (~185PS) is now available in the Mazda6 (approx. the same power as the 2.0 SA-X engine, but more torque I think, so a more comfortable drive, but at the expense of mpg), but the really nice 2.5T SA-G petrol is only available in bigger cars sold in North America and Down Under, where the standard 2.5 is also available for the Mazda 3, and probably why it is one of the best-selling cars in Australia (selling far more than in the UK).
Damn (pardon my French) Euro emissions rules (corporate CO2 fines)!
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The non SA-X version in the gen-4 car (still 120PS) is a variation on that in the gen-3 car and is actually slower to 60 (by some margin) as well (just look it up in the Car by Car Reviews section). Whether that's borne out in the real world is another matter.
Strangely enough I first started looking at the website www.zeperfs.com/en/ following a similar comment from you (another time, another place) about Mazda's quoted 0-62mph figure being "much" better for the Gen 3 120ps than the Gen 4 122ps (8.9s vs 10.4s)!
If you care to take a look you will find extensive real world performance figures for all the Mazda variants present and past. You can also set up direct comparisons for them. The real data show that small differences in 0-62 times provided by Mazda for different models are totally meaningless. Looking at the average data on there shows the Gen 3 and 4 with the same engine rating are identical (9.6s vs 9.7s). In fact they show the Gen 4 car slightly better overall for acceleration and track performance and a bit more ahead for flexibility.
Several of the Mazda variants of interest have quite a lot of values for each "point on the chart" and the spread between individual test values is often larger than differences between different engines, again highlighting that it is pointless to read too much into small differences in acceleration times. Far more useful to most drivers (excluding boy racers) is the in-gear acceleration and flexibility (or lack of it). In that respect Mazda have come a long way since your 1.6 Gen 1 but as I mentioned earlier still cannot compete with many small turbo engines. Not even with their latest 2.0 SA-X version (unless you are interested in speeds well above the UK 70 mph limit).
Edited by misar on 11/01/2020 at 21:11
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I brought this very issue up with HJ after the gen-4 car was introduced - I thought the 0-60 (or 62 depending on if you take the Euro way of 0-100kph instead) figures were ridiculous, given the 2.0 SA-G engine was not much different from the gen-3 car's. I mean, 10.4 is only 0.7 sec slower than my old car's figure of 11.2.
The (real world) figures you quoted of 9.6 / 9.7 sec for the newer versions seems to bear out my experience during the test drive that the car was not that quick in comparison to mine. I think that Mazda, engine-wise, have gone down the path that Toyota have gone decades ago in making them just reliable 'everyday cars', at least as far as the petrol-engined ones are concerned.
Odd why they persist so much with making them excellent handling cars, but don't develop any kind of sportiness (or at least restrict them to a few markets only). Maybe they believe, as a smaller manufacturer with less financial clout, they cannot afford the greater R&D and backup possibly needed to cater for small capacity turbo petrol engines.
The daft thing is that they took a big leap by going heavily into diesels, which didn't work out well given their seemingly poor reliability/longevity record, and thus they are now reducing them in the range quite significantly, and not just because of Dieselgate and new environmental laws/bans in cities for older cars.
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Odd why they persist so much with making them excellent handling cars, but don't develop any kind of sportiness (or at least restrict them to a few markets only). Maybe they believe, as a smaller manufacturer with less financial clout, they cannot afford the greater R&D and backup possibly needed to cater for small capacity turbo petrol engines.
Only Mazda can tell us their reasoning. I wonder if they are lead by obstinate old men like me who still believe a large, free reving engine linked to a great manual gearbox feels more sporty than a toy 3 cylinder engine with turbo lag! If you do a real world comparison on the basis of motors with equivalent power you will find that the Mazda approach lacks only in-gear flexibility at low revs in the higher gears. A performance hit which is reversed if you simply change gear. I doubt anyone would define "sportiness" as the ability to slog up a bit on an incline in 6th gear.
All of this can be demonstrated by comparing the Mazda 3 2.0G at 122ps with the Focus 1.0 Ecoboost at 125ps (a direct competitor which I seriously considered). Even the real world fuel consumption is much the same for the two.
www.zeperfs.com/en/duel7501-7858.htm
www.zeperfs.com/en/match7501-7858.htm
Of course, the Focus has more engine options if you want just a bit more power. However, you may be interested to know that in Sweden the standard 2.0G M Hybrid has already been uprated to 150ps and Mazda plan to introduce it across Europe (possibly as an extra engine option elsewhere). Nevertheless I agree with you that if Mazda want real high performance cars at the very top of their ranges, like the "hot hatches" produced by Ford, VW, etc, they need to add a turbo to their 2.0 litre engine.
Edited by misar on 12/01/2020 at 21:00
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"...if Mazda want real high performance cars at the very top of their ranges, like the "hot hatches" produced by Ford, VW, etc, they need to add a turbo to their 2.0 litre engine."
In fact the new Mazda Skyactiv X 2-litre petrol engine has a small supercharger which operates when the engine is in compression-ignition mode, but its function is merely to facilitate the operation of compression-ignition, so it doesn't act like a turbocharger.
It seems clear Mazda's philosophy is to avoid "sportiness" and concentrate on driveability, economy, reliability (ignoring the diesel problems) and a pleasant all-round experience for the driver and passengers.
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I mean, why would you overtake someone on a one lane-each-way road sedately?
Of course like you I would not but once again you need to consider the real numbers.
Leaving aside tractors or a bunch of cyclists, I would not normally need to drop lower than 3rd to overtake another car or truck on the open road. With mine (which may not be much different from yours in this respect) at 4000 rpm it is travelling at 61 mph. The UK-wide speed limit on your one lane-each-way roads is 60 mph. Hence as I said earlier I rarely (not never) need to rev much higher in normal driving.
Rest assured that should there be a real need to drop into 2nd while overtaking I and the car will happily try harder!
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One of the joys of motoring in the 1970s with typically 1960s bangers was that they could be driven to the max without necessarily going very fast (but without much crash protection!) - eg: Ford Anglia, Triumph Herald, Hillman Imp etc.
Big bore exhaust would make a loud noise as revs increased and skinny tyres wold squeal convinncingly in corners.
Today most even fairly modest cars will comfortably crack 120mph, accelerate to 60 mph in under 10 sec, corner like supercars of old etc. They are entirely capable of outperforming the environment in which they are used due to:
- speed cameras
- congestion on many/most roads
- vehicle performance often exceeds the etc ability of the driver
So the only time I floor the go pedal in my 130bhp hatch is sometimes to gain speed to match the traffic if joining motorways. The accelerator may get a short prod overtaking a tractor or farm lorry on rural roads - otherwise I almost never exceed 3000 rpm. Sad isn't it!!
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Probably why track days are so popular these days.
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Thanks for reminding me why driving is no longer enjoyable even with today's levels of performance and comfort which were unimaginable back then. I thought it was down to getting old!
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Today most even fairly modest cars will comfortably crack 120mph, accelerate to 60 mph in under 10 sec, corner like supercars of old etc. They are entirely capable of outperforming the environment in which they are used due to:
- speed cameras
- congestion on many/most roads
- vehicle performance often exceeds the etc ability of the driver
So the only time I floor the go pedal in my 130bhp hatch is sometimes to gain speed to match the traffic if joining motorways. The accelerator may get a short prod overtaking a tractor or farm lorry on rural roads - otherwise I almost never exceed 3000 rpm. Sad isn't it!!
This is why, in order to have fun and enjoy driving, you need a small light city car. A few years ago we got a Citroen C1 loan car while ours was in the bodyshop. Absolutely brilliant, fantastically eager, responsive, very quick off the line with so little mass to shift.
Power?, 70bhp, so not enough to get into serious trouble, but plenty for maximum smiles!.
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<< This is why, in order to have fun and enjoy driving, you need a small light city car. >>
Maybe that explains the steady rise in prices for the trickle of 205 GTIs emerging from barns everywhere ? All those cars came in at under a ton (weight, that is).
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