REVOLUTIONS PER MINUTE

toysky, Mar 25, 12:07pm
I currently rev at 3300 at 100kphusing tires that are 175x 15

If i put on a 16 or 17 inch whell could I drop the revs by 500 odd at same speed/

mrfxit, Mar 25, 12:52pm
Blimin muppet.
Sorry but to have to ask a question like that without ANY reasonable info FIRST requires you to go & hug mummy & then Go here to do your OWN calculations.
http://www.1010tires.com/TireSizeCalculator.asp!action=submit

After that, & you DO go ahead with this insane idea, then I really hope you have a full box of tissues for when you get snapped repeatedly for speeding.

scotthurst01, Mar 25, 12:59pm
Get a car with better gear ratios.

mrfxit, Mar 25, 1:02pm
Oh yea . & more tickets for holding up traffic on hills.

attitudedesignz, Mar 25, 1:03pm
Having a bad day mate LOL!

mrfxit, Mar 25, 1:07pm
LOL, yea THAT & the muppets are finely getting to me.
Flippin traffics getting nastier every day at the moment with the latest fuel prices.

jezz43, Mar 25, 1:29pm
tyre size can only be altered a specific amount before it plays havoc on the suspension. i think its about +/- 10mm on your tyres before it starts to handle like a unreliable bag of crap.i had issues with a 4wd avenir, was originally 185/64R14 tyres and some muppet put on 235/45R17s. never handled well till i changed back to original size

toysky, Mar 25, 1:33pm
iTS PURELY FOR A FUEL SAVING THING I,M LOOKING AT . DRIVE 750K A WEEK HIGHWAY STRAIGHT ROADS , FIGURE PERHAPS DROP REVS BY 500 ODD MUST SAVE GAS

jasongroves, Mar 25, 1:37pm
Change your diff ratios.if possible.
Nobody here has a clue what vehicle you are talking about so VERY hard to be of any real help.

a18a, Mar 25, 1:40pm
lower revs doesn't always mean more economy

mrfxit, Mar 25, 1:51pm
IT WON"T SAVE GAS

it WILL make you use MORE gas = Fuel .
Because you will have geared WAY OVER the optimum gearing needed for efficient economy & power combination.
Higher gearing requires MORE power . Not less.
The ONLY way it can work on tire size alone is IF . (& thats a blimin BIG IF) the original vehicle is geared lower then optimum "as it come out of the factory"
OR
You increase HP & torque by some other reliable means

mrfxit, Mar 25, 1:54pm
Carefully modded vehicles
Driving slower
Driving gentlier
Tires at the optimum pressures to suit the vehicle & loads/roads
Less weight in the vehicle (stop carting the MIL around)

mrfxit, Mar 25, 1:57pm
Good that you asked first because .

If you simply went ahead & did it, then that would have been an expensive mistake & looked an even bigger MUPPET.

Now don't get me wrong here . I LOVE muppets & jim Henson, BUT leaving a muppet to it's own devices is ASKING for trouble.

attitudedesignz, Mar 25, 2:10pm
You're certainly on form today hehe.

Must admit i get a bit like that when Muppets ask "How much will it cost to paint my car!" And thats all the info we get.

johnf_456, Mar 25, 2:29pm
Nice self promotion.

thejazzpianoma, Mar 25, 2:34pm
You wouldn't have to add much to your sale price to swap it out for my favorite wee 2001 or newer Punto. A manual one will do 5l/100km and the CVT just a fraction more.

CVT will cruise happily at 1950RPM at 100km/h but gets away with it because it can incrementally add a few revs when you start to go uphill etc.

Little bit of road noise though so its a case of economy over comfort with our course chip roads but you could always put some soundproofing in.

wrong2, Mar 25, 2:52pm
if you drop down 300 rpm , you might have a fuel saving

some cars ARE lower geared than they should be

i said SOME. because your car has a torque curve, dropping your revs at 100 km/h too much will drop you down the curve & make the engine work harder - icreasing your cars fuel consumption

a slight drop in revs may improveyour economy - itstune dependant

toysky, Mar 25, 3:13pm
Fiat Punto huh

1fordluva, Mar 25, 3:42pm
What sort of bloody car is it!
Have to agree mrfixit.muppetts lol

jasongroves, Mar 25, 7:12pm
He actually did say in a post above.but 'someone' told the TM police.
Its a: Ford LASER TX3i 1990

wrong2, Mar 25, 9:07pm
they are the 1600 ! thats about right revs for that car

might be down on compression & its raised the revs its pulling by 50 or so maybe - but it will be stuff all

toysky, Mar 26, 1:56am
Its the dohc 1800

johnf_456, Mar 26, 3:45pm
Yip wrong is right, its normal for that sort of engine.

rlnhrd, Sep 5, 12:47pm
just pump your 185s upto 800psi