[locusjag]

Originally Posted by haisaikat

This is exactly the kind of thread I was looking for. And indeed some great suggestions provided. I have a related question. If both cars are torque converter equipped AT then will a Naturally aspirated petrol fair against turbo Diesel engine in higher altitudes where air density is supposedly less than on plains

Originally Posted by haisaikat

Thanks. But my question is different, in high altitudes where air density is a less who will be more impacted, a naturally aspirated engine or a turbo charged one since both will have the same source to draw air from.

I understand that a Turbo equipped engine will fare better than a Naturally Aspirated counterpart, provided that the driver knows well enough to keep the turbo spooling. Depending upon the vehicle's turbolag zone, this may or may not be possible when starting from a full stop on a hilly incline. There are people on this forum who swear by a naturally aspirated engine for the hills purely for its low-end grunt; the turbolag (a.k.a deadzone) on some diesel cars totally negates their on-paper higher engine power, while some naturally aspirated engines with lower power on paper tend to pull cleanly up steep slopes from a full stop, even if they do suffer from loss of power owing to thinner air at higher altitudes.

Personally, I'd like to think that my TUV 300, with its two-stage turbo, would keep chugging at high altitudes. There is no deadzone for the turbo in the TUV 300/plus models...

If you want to, please check out the last season's episode on the Grand Tour where Clarkson drove a stock Lamborghini Urus up a snowy European ski slope. He specifically mentioned the low-end grunt brought on by its turbo; the Urus didn't struggle to climb the steep snowy surface.

[Venkatesh.H]

Originally Posted by haisaikat

This is exactly the kind of thread I was looking for. And indeed some great suggestions provided. I have a related question. If both cars are torque converter equipped AT then will a Naturally aspirated petrol fair against turbo Diesel engine in higher altitudes where air density is supposedly less than on plains

It is always Turbo Diesel engine perform better compared to NA petrol engine. Turbo assist in feeding more air inside engine cylinder even at high altitude, where air density is lesser.


Venkatesh.H

[sgiitk]

No real issues. Only keep it in S (sports) mode. Then you get some engine braking. Of course you can shift down from D. Remember as you shift down the reverse braking also improves.

[haisaikat]

If there is a slow / standstill traffic on a uphill / downhill road / incline (example - city flyovers), is it recommended to use Park mode on auto gears or just engage the hand brake? From my own experience in Hyundai Getz which is of course manual gearbox, I have seen regular usage of handbrake makes its clinging capability weaker and I have to visit the Service Center and order for adjustment / tightening of the same.

Another question, if there is near freezing temperatures outside, I read earlier on this forum that there are ways to lower the freezing point of diesel by using additives or buy readymade "hilly" (I made up this name) diesel from the petrol pumps highers. Similarly AT gearboxes that use internally fluids for operating will they be prone to similar problems?

Originally Posted by sgiitk

No real issues. Only keep it in S (sports) mode. Then you get some engine braking. Of course you can shift down from D. Remember as you shift down the reverse braking also improves.

Thanks, is this only applicable for downhill? or are you recommending for uphills too? In cars that do not have hill descent control I think the sports mode may be useful for downhill.

A related question for utilizing engine braking is that does it not put more stress on the gears? I recall from my Hyundai Getz owner manual it was written that for incline braking or holding (even in standstill) we should not use clutch / gear and instead use Hand brake to prevent wear / damage of parts but then again that was 12-15 years old technology and that too manual car. Any thoughts

[sgiitk]

@haisaikat; depends on how much shifting you can tolerate. I use S for both climb and descent. Some amount of engine braking does help.

[heydj]

It depends if features like Hill Assist etc. are there or not. E.g. In my Rapid DSG if car is stopped while climbing due to traffic then upon taking foot from brake car will not roll back.

Similarly while going down engine braking happens i.e. car slows by itself if foot is taken away from accelerator this leads to less breaking fatigue.

[haisaikat]

I am trying to contemplate between the Innova Crysta 2.7 petrol AT which is naturally aspirated and provides peak torque of 245 NM at 4000 RPM vs the 2.8 Diesel AT which is turbo charged and generates 360 NM at 1200-3400 RPM range. From the torque curves of the Innova diesel AT it is evident that low RPM non turbo zone torque of the diesel is not much behind to the peak torque of the petrol. Low end torque of the petrol is not published anywhere emailing to Toyota support yielded nothing. I am not a regular off roader nor that I live in the hills but if I am to make a purchase based on daily runs the at less than 1000 KM per month the petrol seems better suited.

However if I do plan to go places I have to make sure the car would be capable of pulling under full load in situations like hilly inclines with AC on, hence all of these asks. The petrol is lighter and peak power to weight ratio of petrol vs Diesel is also similar. Of course a naturally aspirated petrol and a small turbo big displacement Diesel may or may not be similarly impacted on performance while in low air density situations at higher altitudes.

Can anyone make any suggestions?

Here is the torque curve for the Diesel AT which is a bit higher tuned for Fortuner and Hilux of Toyota, the version in Innova is a bit toned down form of the same. Hence this curve represents marginally higher torques.

[jav]

Originally Posted by haisaikat

I am trying to contemplate between the Innova Crysta 2.7 petrol AT which is naturally aspirated and provides peak torque of 245 NM at 4000 RPM vs the 2.8 Diesel AT which is turbo charged and generates 360 NM at 1200-3400 RPM range

Hi let my share my point of view on the diesel

I have a 2.8Z and the engine is a beast, i have driven in very steep hills including stopping on some crazy hair pin turns, it has hill hold assist and it moves without any issues that too in eco mode with full passengers and ac on all the time, i do most of hill driving on S (sequential not sport) mode and it performs almost like a manual if not better. I usually dont use power or normal mode especially on hills because it picks up speed so fast that you wont notice your moving so quick until you look at the speedo.


Also in S6 mode i am getting 18.7 kmpl with 7 passesngers on 2 lane highways with full time ac



i have not driven the petrol so cant comment on its performance
hopefully i have answered some of your questions do feel free to ask if you have any more .

[haisaikat]

Originally Posted by jav

Hi let my share my point of view on the diesel

I have a 2.8Z and the engine is a beast, i have driven in very steep hills including stopping on some crazy hair pin turns, it has hill hold assist and it moves without any issues that too in eco mode with full passengers and ac on all the time, i do most of hill driving on S (sequential not sport) mode and it performs almost like a manual if not better. I usually dont use power or normal mode especially on hills because it picks up speed so fast that you wont notice your moving so quick until you look at the speedo.

The Z model has hill hold but not in G variant since I am looking for 8 seat configuration. I understand hill hold is very useful. But your feedback on the diesel pulling power is reassuring. Hoping to find someone for petrol feedback too.

Regarding the mileage, it's off topic on this thread so sending you a PM

[maven]

I used to think Manual would be a better as one has greater “control” and the Auto box would take time to “think”.

Having driven an Auto at 6700 Ft. and 7800 Ft. encountering steep gradients, plenty of hairpin bends, an Auto is a better choice over manual in the hills. Downhill sections are easier to drive as you release the accelerator and let the engine do its bit to slow you down. It’s definitely less tiring. And, if it’s a good auto box there are rare “damn it should have upshift already” instances.