sudeepd

Maruti recommendations. Are they correct?

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I read in Dzire VDi's Owner Manual the following.

In the "Operating Your Vehicle" Section (Section 5),

the Downshifting maximum allowable speeds is given as below:

photo12z.jpg

photo13n.jpg

In above pics, it is given that

 For Petrol Engine Swifts/Dzires=>

If you are driving at speeds of above 180kph in 5th gear don't downshift to 4th unless you reduce speed below 180kph.smiley36.gif

If you are driving at speeds of above 135kph in 4th gear don't downshift to 3rd unless you reduce speed below 135kph.smiley36.gif

If you are driving at speeds of above 90kph in 3rd gear don't downshift to 2nd unless you reduce speed below 90kph.smiley36.gif

If you are driving at speeds of above 50kph in 2nd gear don't downshift to 1st unless you reduce speed below 50kph.smiley36.gif

For Diesel Engine Swifts/Dzires=>

If you are driving at speeds of above 155kph in 5th gear don't downshift to 4th unless you reduce speed below 155kph.smiley36.gif

If you are driving at speeds of above 115kph in 4th gear don't downshift to 3rd unless you reduce speed below 115kph.smiley36.gif

If you are driving at speeds of above 70kph in 3rd gear don't downshift to 2nd unless you reduce speed below 70kph.smiley36.gif

If you are driving at speeds of above 40kph in 2nd gear don't downshift to 1st unless you reduce speed below 40kph.smiley36.gif

Now as for Air Cleaner Element Cleaning Schedule.

photo14o.jpg

The above image shows that Maruti Suzuki Recommends that Swifts/Dzires Diesel Engines don't require Cleaning.smiley36.gif

ONLY Petrol Engines REQUIRE Air Cleaner Element Cleaning.smiley36.gif

VERY GOOD (IN FACT THE BEST) RECOMMENDATION MADE BY MARUTI SUZUKI.

KEEP IT UP GUYS.smiley32.gifsmiley32.gifsmiley32.gifsmiley32.gif

sudeepd2009-03-09 10:09:01

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There's nothing "stupid" about any of these recommendations.

- the maximum speed for downshifting is actually very important (no laughing matter). If you are doing 100km/h and downshift to 1st/2nd at that speed (by accident/intention), you are risking damage you your drivetrain. You'll break something in the transmission and will over-rev your engine. They are specifying it in the manual so that people who've just learnt driving don't make this mistake and then come running back to claim warranty on their new car.

- As for the "don't clean the diesel air filter" bit - thats because you are supposed to replace it. A paper filter that's cleaned by pressurized air isn't as good as a new one.dtandon2009-03-09 10:26:01

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As said by dtandon, i don't think that there is any "stupid" in these recommendations. If these are not followed, it'll cause damage. These are just maximum possible speeds and MS is not asking you to downshift only at the specified speeds(they are just asking not to cross them or can i say max speed on every gears).

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@dtandon and CC

Look guys,

              All of us who drive cars know that we should not down shift at high rpms to avoid damage to engine and skidding of tyres.smiley1.gif

But I guess MS does not know this point(that no one will try to downshift at such high rpms (more than 4000-5000) unless the driver has Hard Racing intentionssmiley2.gif.

smiley36.gif

So don't it take personally.

Now for Air Filter Element Cleaning.

You said "A paper filter that's cleaned by pressurized air isn't as good as a new one".

OK then tell me why MS recommends Cleaning the AFE of Petrol Swift/Dzire only.

Why MS recommends the Petrol Engine Air Filter Element requires Cleaning and Diesel Engine Air Filter Element does not require cleaning?

Same criteria should apply to the Air Filter Element of both Petrol and Diesel.

Indigo Petrol and Diesel share same type of Air Filter and require same interval of Cleaning and also of Replacement.

Indigo has Paper filter for both Petrol and Diesel but Service recommendation for both are same (Cleaning every 5000kms and Replacement at 40000kms).

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@dtandon and CCLook guys' date='              All of us who drive cars know that we should not down shift at high rpms to avoid damage to engine and skidding of tyres.

[/quote']

Please see my comment about new drivers. Also, mistakes happen - I know a friend who shifted to 1'st at 100km/hr during a panic stop in his car - the consequences weren't good.

What's this about "skidding of tires" - tires have nothing to do with this.

As for the air filters - I'm sure you know that the diesel engine is sourced from Fiat and the petrol is in-house.

Petrol and diesel engines are different and its best not to generalize maintenance parameters (different machines have different tolerances). dtandon2009-03-09 11:22:28

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What's this about "skidding of tires" - tires have nothing to do with this.

If you are driving at speeds of 60kph in 4th gear and suddenly shift to 2nd without reducing the speed' date=' what will happen to the Front Wheels (in case of FWD)? Wont they skid as the rpm has increased suddenly from around 2000rpm to say 4500-5000rpm? The tyres will not be able to handle the EXTRA power produced at 4500rpm in 2nd when sudden shift (from 4th to 2nd at 60kph) is done.

As for the air filters - I'm sure you know that the diesel engine is sourced from Fiat and the petrol is in-house.Petrol and diesel engines are different and its best not to generalize maintenance parameters (different machines have different tolerances).

I very well know that Swift's Petrol is in-house and Diesel is sourced from Fiat.

But that does not mean only petrol's air filter needs cleaning and not diesel's.

 Fiat has just provided the Engine and not the complete assembly which sits under the hood. Except Engine all other parts are made by MS.

My question is

So why MS is recommending Diesel does not require Cleaning and Petrol needs cleaning?

Petrol and diesel engines are different and its best not to generalize

maintenance parameters (different machines have different tolerances).

So my dear friend please tell me why Petrol Indicas, Petrol Indigos, Diesel Indicas, and Diesel Indigos share same Air Filter.

Please don't tell to save cost. Please tell some other justification.

Also if you observe carefully last pic, it is given "A dirty air cleaner will cause the fuel supply system to supply too much fuel to the engine for the amount of air being supplied. The result is waste of fuel due to incomplete combustion".

   It is not mentioned to clean either Petrol or Diesel Air Cleaner Element in this pic.

   But the prices of Air Cleaner (as of ACI Spare parts Survey) are Rs.190/- for Petrol Engine and Rs.259/- for Diesel Engine.

In above pic, neither Petrol Air Cleaner is recommended to Clean nor Diesel Air Cleaner.

Thanks.

sudeepd2009-03-09 12:00:54

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If you are driving at speeds of 60kph in 4th gear and suddenly shift to 2nd without reducing the speed' date=' what will happen to the Front Wheels (in case of FWD)? Wont they skid as the rpm has increased suddenly from around 2000rpm to say 4500-5000rpm? The tyres will not be able to handle the EXTRA power produced at 4500rpm in 2nd when sudden shift (from 4th to 2nd at 60kph) is done.

[/quote']

Thats only in you still have the throttle floored after the gearchange - otherwise the extra stress in only at the gearbox/engine as they reach redline RPM's.

I very well know that Swift's Petrol is in-house and Diesel is sourced from Fiat.But that does not mean only petrol's air filter needs cleaning and not diesel's.?Fiat has just provided the Engine and not the complete assembly which sits under the hood. Except Engine all other parts are made by MS.My question is So why MS is recommending Diesel does not require Cleaning and Petrol needs cleaning?

A new air filter would provide better airflow than one that has been cleaned. The engines have sensors that (to some extent) can adjust to the amount of air coming in from the filter and inject fuel accordingly. The diesel engine (and turbo) might not be as adaptable to reduced airflow as the petrol - hence they recommend a change and not a cleaning. Also' date=' Maruti will obviously quote Fiat on what the proper filter maintenance is - since its a Fiat engine and they know best.

(I would be surprised if the Indica Vista or the Palio 1.3 have a different recommendation)

So my dear friend please tell me why Petrol Indicas, Petrol Indigos, Diesel Indicas, and Diesel Indigos share same Air Filter.Please don't tell to save cost.

Nothing wrong with sharing the same filter (In the Maruti world - the carb 800, carb Zen and M1000 all share the air and oil filter) and as for the reason - You answered your own question. If "one size fits all" then why have two.

But maintenance schedules can differ.

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Thats only in you still have the throttle floored after the gearchange - otherwise the extra stress in only at the gearbox/engine as they reach redline RPM's.

But if the rpm increases to double suddenly' date=' won't the tyres spin faster than before?

And yes I don't mean that the throttle being floored even after shift. 

I very well know that Swift's Petrol is in-house and Diesel is sourced from Fiat.But that does not mean only petrol's air filter needs cleaning and not diesel's. Fiat has just provided the Engine and not the complete assembly which sits under the hood. Except Engine all other parts are made by MS.My question is So why MS is recommending Diesel does not require Cleaning and Petrol needs cleaning?

A new air filter would provide better airflow than one that has been cleaned.

Agreed.

The diesel engine (and turbo) might not be as adaptable to reduced airflow as the petrol - hence they recommend a change and not a cleaning.

Then like Maruti' date=' why don't other manufacturers recommend same for their Diesel Engine Cars?

(I would be surprised if the Indica Vista or the Palio 1.3 have a different recommendation)

I will check out with local dealer for Vista Quadrajet and Linea Advanced Multijet (I don't think local dealer would have kept Palio as Demo).

Lets See what Tata suggests for Vista Quadrajet and Fiat for Linea Advanced Multijet.

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But if the rpm increases to double suddenly' date=' won't the tyres spin faster than before?And yes I don't mean that the throttle being floored even after shift.?[/quote']

Look at it this way - the tires, axle and the output shaft of the gearbox are rotating at the same speed (same as before the downshift) - but the gearing has changed. So to compensate - the rest of the gearbox and the engine have to spin faster (and get to the higher RPM in an instant)

eg. (for illustration only - the numbers are not exact)

Suppose, you are doing 100Km/hr in 5th gear at 2500 rpm in a car that redline's at 4500 rpm. You engage 2nd gear and let go of the clutch ->

The tires and axles will still be rotating at the same speeds as before - but in 2nd gear, the engine must do 6000 rpm to get to 100km/hr.

So - what happens - something in the drivetrain snaps because you took the engine and the transmission from 1200 rpm to 6000 rpm (above redline) in the blink of an eyelid.

The safe downshift speed is calculated from the maximum speed that the vehicle can attain in a particular gear.

So if car X does a maximum of 40Km/hr in first gear and 80km/hr in second gear. Then its unsafe to shift from 5th,4th,3rd gear to 2nd gear at any speed above 80km/hr and unsafe to shift to 1st gear at any speed above 40Km/hr.

It because the engine and transmission will experience forces that they were not built for.

Then like Maruti' date=' why don't other manufacturers recommend same for their Diesel Engine Cars?

[/quote']

Not all machines are built the same.

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But if the rpm increases to double suddenly' date=' won't the tyres spin faster than before?And yes I don't mean that the throttle being floored even after shift.?[/quote']

Even if it spins, it spins for just a second or so and the speed will dramatically come down.

But if the speed is more than what specified on Dzire's manual, then as said by Dtandon, the mechanicals will be damaged.

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Today I went to Tata Dealer and asked for Owner's Manual of Vista Quadrajet (Fiat Diesel Engine).

In the Manual, it is mentioned that the Air Filter Needs Cleaning Every 10,000kms and Replacement Every 40,000kms.

Now would some Experts please explain-->

   Why Maruti Suzuki mentioned in the Swift/Dzire Diesel's Manual that its Air Filter DOES NOT Need Cleaning but only Replacement

                                  AND

   Tata Motors mentioned in the Vista Quadrajet's Manual that its Air Filter DOES Need Cleaning Every 10,000kms and Replacement Every 40,000kms?

Why Maruti Suzuki and Tata Motors are recommending Different Maintenance Procedure for the SAME Fiat MULTIJET Diesel Engine (or should I say Air Filter of the SAME Fiat MJD Engine)?

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Beats me. Maybe its some Maruti philosophy which is still unheard of.

 

And about the Downshift speeds. Its acurate. Actually its a little more than what should be usually done.

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Beats me. Maybe its some Maruti philosophy which is still unheard of.
But why MS is recommending people to Replace the Air Filter Directly instead of Cleaning? How can a Air Filter remain Active till the Replacement Interval?

I guess the Service Interval is Every 5000kms. So it makes Complete Sense to Clean the Air Filter at least Every 5000kms (More Frequently in Dusty Conditions). How could the Air Filter Remain ACTIVE till 40' date='000kms without Cleaning?

As for the "don't clean the diesel air filter" bit - thats because you are supposed to replace it.
If we are supposed to replace it, why other Manufacturers (other than MS) recommend to clean the Air Filter every 5,000kms and replace every 40,000kms?

Does the Air Filter of MS is of Such Inferior Quality that it has to be Replaced Directly instead of Cleaning?

A paper filter that's cleaned by pressurized air isn't as good as a new one.

Agreed that A paper filter that's cleaned by pressurized air isn't as good as a new one. Then why other Manufacturers Dont Recommend the Same thing as MS?sudeepd2009-08-21 14:44:21

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