Diesel vs gas torque/mph graph

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Guest2019C20

I have updated my CX-5 torque vs mph graph, with numbers for the diesel engine. I assume that gearing stays the same as the gas engine.

Diesel is the light gray lines. Note that if you keep the gas engine above 4200 rpm, you will get *faster* acceleration than the diesel, except below 20 mph. (Hmmm, does the diesel weigh more?)

Diesel torque from the graph presented here: http://www.versatune.net/forum/viewtopic.php?f=21&t=1045

Torque is the Y axis, MPH is the X axis. These numbers do not account for driveline loss, except as shown in the dyno charts used to generate them.

33363489802_76774b6c97_k.jpg
 
A little more explanation...

The diesel torque peaks at 2600 rpm.
The gas torque peaks from 3200 to 4200.
The diesel's 1st gear torque intersects the gas 1st gear torque at 21 MPH.
 
Data from Mazda Australia website - at least here, the individual ratios and final drive ratios are different. Likely that they are a,so different in other markets.

Petrol 2.5L 2016
Auto gearbox ratios, final drive ratio, power and torque, vehicle weight

Gear ratio (1st) 3.552
Gear ratio (2nd) 2.022
Gear ratio (3rd) 1.452
Gear ratio (4th) 1.000
Gear ratio (5th) 0.708
Gear ratio (6th) 0.599
Gear ratio (final drive) 4.325
Gear ratio (reverse) 3.893
Kerb weight 1,630kg
Maximum power 138kW @ 5,700rpm
Maximum torque 250Nm @ 4,000rpm

Diesel 2.2L 2016 model
Auto gearbox ratios, final drive ratio, power and torque, vehicle weight

Gear ratio (1st) 3.487
Gear ratio (2nd) 1.992
Gear ratio (3rd) 1.449
Gear ratio (4th) 1.000
Gear ratio (5th) 0.707
Gear ratio (6th) 0.600
Gear ratio (final drive) 4.090
Gear ratio (reverse) 3.990
Kerb weight 1,705kg
Maximum power 129kW @ 4,500rpm
Maximum torque 420Nm @ 2,000rpm

The only performance figures I could find (not Mazda official claims, but as tested by journalists) with a very quick search just now says:

0-100km/hr (60mph approx)
2.5L petrol = 8.5 or 8.7 sec
2.2 diesel = 8.0 sec

Real time performnace and acceleration on the road? The 2.2 diesel auto KILLS the 2.5 petrol. Been there, tried that. Had both in our fleet at work. Those that got the petrol then drove my diesel, left regretting it.
 
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Moonlighter, thanks for the gearing! I'll redo my chart and post a 2nd version.

When comparing acceleration performance, it's always good to remember that HP trumps torque, if the higher-horsepower engine is geared lower to take advantage of it.

I suspect that driving the diesel (non-drag-race), with fantastic low-rpm torque, would be quite enjoyable!
 
Here's the revised graph.

I noticed that your final drive ratio for the gas engine is different than mine. My speedo/tach agree with my gearing chart, so there might be differences in US models...

33394063001_0ba73cfddb_k.jpg
 
I know that hp trumps torque ......

But,

only 9 extra kw from the 2.5 (8.5% more)

vs

170nm extra torque from the 2.2! (60% more!!)
 
You can't ignore kerb weight or gearing.

Traditionally in the UK the diesel engine is heavier, and has higher gearing, compared to a petrol.
 
One thing I don't like about the Mazda diesel is that you need to be more conscious of the rev range than with other diesels I've driven. Rev too high and you really do lose power.

I do like this car a lot and, round town, it is very nippy. I won't buy another Mazda diesel though; as I said, you need to massage the car onto an on ramp at full power, and accelerating in the 60-90mph range is slower than I would like. My previous Volvo was a lower power and smaller plant and tangibly faster in this range, so it's probably gearing.

* one thing to note, I have the 150bhp diesel. I wonder if the 175bhp is better in the respects I mention? Anyone?
 
I don't understand that graph, Mazda have emailed me with an excel graph back in 2013 which shows max torque at 2000 rpm, which they also publish in their brochure.

Are they saying the engine has now changed for 2015, mazda also quote power in PS or Kilo watts.

A little more explanation...

The diesel torque peaks at 2600 rpm.
The gas torque peaks from 3200 to 4200.
The diesel's 1st gear torque intersects the gas 1st gear torque at 21 MPH.
 
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One thing I don't like about the Mazda diesel is that you need to be more conscious of the rev range than with other diesels I've driven. Rev too high and you really do lose power.

I do like this car a lot and, round town, it is very nippy. I won't buy another Mazda diesel though; as I said, you need to massage the car onto an on ramp at full power, and accelerating in the 60-90mph range is slower than I would like. My previous Volvo was a lower power and smaller plant and tangibly faster in this range, so it's probably gearing.

* one thing to note, I have the 150bhp diesel. I wonder if the 175bhp is better in the respects I mention? Anyone?

Mazda don't do a 150bhp or 175bhp, its 148bhp or 173 bhp approx. I have to say i don't find the engine lacking in acceleration or pulling power, but i have the 175ps, the 150ps has the torque flatlined over a range mentioned in the brochure 1800 to 2600 rpm from memory, so this could be why you experience reduced power near the top end?
 
Mazda don't do a 150bhp or 175bhp, its 148bhp or 173 bhp approx. I have to say i don't find the engine lacking in acceleration or pulling power, but i have the 175ps, the 150ps has the torque flatlined over a range mentioned in the brocthure 1800 to 2600 rpm from memory, so this could be why you experience reduced power near the top end?

I wonder if there's a safe ecu remap that will get me up to the 173bhp?
 
There are remaps, the 175ps can go over 200ps, but can the mechanics endure the extra power and torque, that's the question, then we have the issue of insurance and warranty.

I'm too old now for all that , so i just buy the most powerful version i can, i do like turbo power though so even if we had the 2.5L option I'm not sure i would buy one.
 
I don't understand that graph, Mazda have emailed me with an excel graph back in 2013 which shows max torque at 2000 rpm, which they also publish in their brochure.

Are they saying the engine has now changed for 2015, mazda also quote power in PS or Kilo watts.

You'll need to post that excel, or ask Versatune... :)
 
I still think, 187 hp will trump 175 hp as far as highway speed passing goes, because Horsepower = torque x RPM / 5252. When doing a highway pass while WOT, you will be high in the RPM range where you will get more horsepower from the NA 2.5 engine than the diesel engine. High torque numbers will give the feeling of really strong acceleration yes, but the horsepower numbers determine at what speed that acceleration is available. High torque, low horsepower means the car is really quick in city driving but will be relatively slower on the highways.

Like I said in another thread though, I would like to be proven wrong. Can't wait to test out the differences in a test drive when the diesel engine becomes available here in the US.
 
It's tough to say. When I'm driving gas engine cars and trucks any more I'm kinda let down compared to driving a Cummins powered truck. Depending on the torque available at highway speed it may surprise you. No I'm used to have 800lb of torque on hand and at highways speed there is no turbo lag so it builds boost and starts pulling pretty quick. If the cx5 diesel can match the passing g power of my work truck even at 4.5 tons and shaped like a brick then I will buy one as soon as I can.

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It's tough to say. When I'm driving gas engine cars and trucks any more I'm kinda let down compared to driving a Cummins powered truck. Depending on the torque available at highway speed it may surprise you. No I'm used to have 800lb of torque on hand and at highways speed there is no turbo lag so it builds boost and starts pulling pretty quick. If the cx5 diesel can match the passing g power of my work truck even at 4.5 tons and shaped like a brick then I will buy one as soon as I can.
How much horsepower does your Cummins powered truck make?

Looking at the performance numbers for a BMW 328d, which was a long term car for Motor Trend, its 45-65 mph time is only 4.1 seconds. That's the same 45-65 mph time as a 2016 Mazda CX-5. For a car with 280 lb-ft of torque, I expected its acceleration to be faster honestly. This is what makes me think 175 hp on the CX-5 diesel might not be significantly fast enough for highway passing compared to the NA 2.5 engine.

These are all just assumptions from me though. I will know for sure once I can test drive one.
 
The truck is 380hp I think but even my older 99 Dodge with 215hp and 430lb always did great on the highway. Of course it all depends on what some people consider hwy passing . I look at more the 60 to 80 run more than the 45 to 65. I need to look up the numbers on my trucks and my old cx7 that was alot of fun.

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The truck is 380hp I think but even my older 99 Dodge with 215hp and 430lb always did great on the highway. Of course it all depends on what some people consider hwy passing . I look at more the 60 to 80 run more than the 45 to 65. I need to look up the numbers on my trucks and my old cx7 that was alot of fun.
Torque is great for city driving, horsepower is great for highway passing. If a car does mediocre in 45-65 mph, it will do the same or slightly worse at highway speeds (60-80 mph). Not to mention, because of gearing, cars will typically be making more torque when doing 45-65 mph passes vs 60-80 mph passes.
 
If that is the case then with full-size trucks it's almost completely backwards. They are quick in the city but the passing power from 60 on up is where they really shine because they are able to build the boost quick and stay on the power curve longer. Before I bought my 2014 I drove the same basic trucks , one with the 6.7 Cummins and the other with the 6.4 hemi, the hemi was a little peppier around town but on the highway the 6.7 was much stronger. Even in comparison with in the truck world. The Chevy and Ford's tend to be quicker in a drag from dead stop but on the highway the Dodge tended to perform better and it had the lower HP. I'm looking forward to driving one when the dealer gets one. The biggest thing will be how they program the trans to do it's job and that where manufacturers have gotten it wrong may time before.

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