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Old 18th September 2007, 08:12   #61
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thanks !

thanks a lot man ,
u made my day!
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Originally Posted by finetuning View Post
Hi TURBOSAM,

I agree with Ricky_63 about pleasure in reading your post.I do feel that it comes from direct experience and sharing without any expectation.I too felt many times the depth of the subject presented in a very simple way.I appreciate your effort.
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Old 18th September 2007, 08:25   #62
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about thinner oil

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hi
we can go for sinthetic oil for better protection and slightly better fuel efficiency
5- w 50 or 10 w 50 is recomanded if u belive in fill it forget it for next 10 k kms
if u put 0 w 40 oil its still better but the problem is it evaporates very fast @ 500-1000 ml/10000kms.
u can definately top up the oil but the lighter fractions which evaporate in the sump and engine ,settle down in the throttle bodies,stepper motors, the planum chamber,tuned length ports inlet ports,inlet valves,and temp and pressure sensors, they may block the vacuum lines if its used somewhere else apart from brake booster<it has a non return valve working in opposite direction, so no probs>as now a days all the crank case vapours are circulated and and consumed by the engines . SO UNLESS AND UNTILL U ARE TOO KEEN ON CLEENING THEM ON REGULAR INTERVALS ... STAY AWAY FROM MOBIL OW40<OR EQUIVALENT>though its still the horsepower boss!!!

Last edited by GTO : 18th September 2007 at 09:25.
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Old 18th September 2007, 08:46   #63
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Quote:
Originally Posted by TURBOSAM View Post
if handlng and grip is not imp plus if u are ready to accept a bit noisey and a bit of harsher ride then, tyres inflated to the max- 1 to-2 psi recomanded by the tyre manufacturer will give you @ 5-15% more distance per lit . apard from lesser rolling resiestence, the tyre will deflect lesser so EFFECTIVE rolling radious will be more by @ 5-7% this difference will NOT show on the guage as number of revolutions will be translated in kms covered but when meter says 100 kms actually u have travelled 105 +kms as with larger radius, u will be needing lesser revolutions to cover the same distence .
its as god as fitting taller tyres ..
whoa, any basis for these numbers?

i really doubt. 1-2 PSi more means 5-7 % higher radius???? we are talking about tires, not baloons. Irags, where art thou?

and you assume that a litre will get you same number of revoltuions with larger tires? what about extra torque the engine will need to handle?
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Old 18th September 2007, 09:05   #64
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Originally Posted by srishiva View Post
Windows rolled down with no AC is better than AC with windows up. AAA in U.S recommends this and its tried and tested.
not really, look at test #4.

We Test the Tips
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Old 18th September 2007, 11:15   #65
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Thanks all (especially TURBOSAM) for more detailed answers to my query.
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Old 19th September 2007, 08:18   #66
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hi

if u read it carefully i said 1- to -2 psi less than max pressure allowed by the tyre manufecturer.
its not 1-2 psi more its generally 8to 10 psi more.
the radial ply tyres have very soft side wall which deforms a lot with load<and causes extra heat too thats why its recomanded to pump up the tyres before hittying express highway>
the drop in rolling resistence will nearly compensate the increase in torque requirement and if u still have doubts then measure the height at 28 psi and 38 psi do the calculations 2*pai*radius .
easies than that.. try yourselves with one tank full test .
Quote:
Originally Posted by vivekiny2k View Post
whoa, any basis for these numbers?

i really doubt. 1-2 PSi more means 5-7 % higher radius???? we are talking about tires, not baloons. Irags, where art thou?

and you assume that a litre will get you same number of revoltuions with larger tires? what about extra torque the engine will need to handle?

Last edited by TURBOSAM : 19th September 2007 at 08:21.
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Old 19th September 2007, 08:41   #67
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hi!

you are always welcome man!
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Thanks all (especially TURBOSAM) for more detailed answers to my query.
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Old 19th September 2007, 08:45   #68
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Quote:
Originally Posted by TURBOSAM View Post
if u read it carefully i said 1- to -2 psi less than max pressure allowed by the tyre manufecturer.
its not 1-2 psi more its generally 8to 10 psi more.
I have observed a difference of upto 4 psi in my car in cold and running pressures.

if I put 1-2 psi less than max, in running it will be more than the max allowed. Are you sure you want to advise others of exceeding manufacturers limit on tyres?

you are talking about an extreme which i have never tried, and I personally suggest you to refrain from testing such measures for a gain in mileage. I won't want to see my tires deformed to such an extent. i would rather have bigger tires to reduce rolling resistance.

safety first bro! any mileage gain is not worth bursting tires on highway.

in spite of all that, I would be interested to see where did you see this data, since you have quoted hard numbers.

Last edited by vivekiny2k : 19th September 2007 at 08:46.
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Old 19th September 2007, 08:57   #69
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crank case vacuum!

if the engine is 1600 cc, if u are idling the car its consuming close to 10% of 1600 cc of capacity BUT its churning 1600 cc air within the engine plus the air in the crank case and sump .
it costs power to rotate something like 4 pistons ,4 con rods ,one crank with 4 balance weights in air at 1000 to 5000 rpm .
when something rotates so fast it creats eddies inside the crank case and . the centre of the eddy is the centre of low pressure . so all the oil which is returning back to sump and which is tossed all over again and again in the sump suspends in crank case air is dumped on the crank shaft. then crank shaft throws it away by hitting it hard!again and again . it costs power too .
the piston ring seal is maintained majorly due to pressure difference between the piston top and crank case.
lower the pressure in the crank case, l more the pressure difference -more better the seal -lesser the crank case blow by better the work done on the piston crown.
if we make an arrangement to suck the air off from the crank case<negative pressure> it will assist better ring seal+marginally better fuel<due to lesser parasitic losses> efficiency+much better oil life<less contamination due to lesser blow by> lesser air to move around WITHIN the engine ..lets say 6 litres at .85bar absolute instead of 6 lit air at 1.025 absolute .
so lesser mass to create trouble !

Last edited by TURBOSAM : 19th September 2007 at 09:01.
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Old 19th September 2007, 09:10   #70
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i get 10km/l in city if i put 30psi and 8.5-9km/l if i put 28 psi. but the ride is like heaven and (slightly towards) earth!!!
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Old 20th September 2007, 08:04   #71
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hi!

the tyre manufacturers recomand the max tyre pressure WITH MAX PAY LOAD when cold .
they know that its going to increase when hot , so considering all the logical possibilities, the max pressure is quated with a lot of factor of safety in reserve.
and u generally never load the car to the max allowed load on tyres .
in short ,its safe too,and its not crossing the mfg.s limits too.
tyre pressure should be checket only when cold.

Quote:
Originally Posted by vivekiny2k View Post
I have observed a difference of upto 4 psi in my car in cold and running pressures.

if I put 1-2 psi less than max, in running it will be more than the max allowed. Are you sure you want to advise others of exceeding manufacturers limit on tyres?

you are talking about an extreme which i have never tried, and I personally suggest you to refrain from testing such measures for a gain in mileage. I won't want to see my tires deformed to such an extent. i would rather have bigger tires to reduce rolling resistance.

safety first bro! any mileage gain is not worth bursting tires on highway.

in spite of all that, I would be interested to see where did you see this data, since you have quoted hard numbers.
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Old 20th September 2007, 08:06   #72
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yes!

there is always a pay off ,and you have to accept it,or forget it !
Quote:
Originally Posted by gemithomas View Post
i get 10km/l in city if i put 30psi and 8.5-9km/l if i put 28 psi. but the ride is like heaven and (slightly towards) earth!!!
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Old 21st September 2007, 14:13   #73
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Quote:
Originally Posted by Ricky_63 View Post
@ TURBOSAM..

It has been a pleasure to read your posts, as they come from an "unassuming" & knowledgeable person (as is evident from all the above posts) - rather than from those of us who think "they are the most knowledgeable" or from those whose each sentence is full of spite & sarcasm.

Cheers
Completely with everything you wrote here.

WOW.. Kudos to TURBOSAM.

After reading through a lot of comments in team-bhp, I'm eagerly waiting to switch to automobile field from electronics field.. Damn interesting is automobile field...
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Old 24th September 2007, 08:02   #74
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most welcome!!!

yes!
we need people who are in this line by passion...
then its getting paid for your dream jobs.
you are most welcome .

Quote:
Originally Posted by mahadev_kc View Post
Completely with everything you wrote here.

WOW.. Kudos to TURBOSAM.

After reading through a lot of comments in team-bhp, I'm eagerly waiting to switch to automobile field from electronics field.. Damn interesting is automobile field...
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Old 24th September 2007, 08:29   #75
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about synthetic oils!

using syn oil has its own benifits.
if we use 0 w 40 or 5 w 50 oil , then the windage losses, pumping losses will get reduced substentially.
0 w 40 is still the horsepower/mileage king..
as parasitic losses are minimum .
BUT 0 w 40 oil evaporates fast due to large number of light fractions present in it. u can ecpect from 500 ml to 4 lit of loss in 15000 kms depending upon the application and engine.
i have exp 250 ml loss in 15000 kms in gtx.
(shell syn lost sunstentially only 1675 ml left out of 3800 ml added in my friends palio gtx within 15000 kms- and there is no oil leakage and no oil somsumption problem to his car. now he has fiat oil and only 28 grams is less in 7000 kms)

more the oil evaporates , more it settles on the valves, combustion chambers, intake manifolds,throttle bodies, temperature and pressure sensors, planum chambers,etc..
using 5 w 50 reduces this problem majorly .
if u get mobil -1 -15 w 50 and use it then its the best ol u can use in the car but it wont give you the milage advantage .
so u can steele down to 5 w 50 with minimum worries!
and u may expect @ 5 to 15 % fuel saving with this oil. if u have trips less than 10 kms and your engine doesnot get up to the oprating conditions(oil is thicker when cold - so 15 w oil or 20 w oil will be much thicker than 5 w oil . so with 5 w oil lesser efforts to pick up, pump, circulate the oil.) then u will benifit @ 15%in pertol cars.
on freeways with long distence trips the benifits will deminish and come close to 5 %

Last edited by TURBOSAM : 24th September 2007 at 08:34.
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