cited:
http://ecomodder.com/forum/showthrea...and-15491.html
1984 Mercedes 2 liter gas, manual transmission 190E
I have changed tyres from 195/60 R 15 to Michelin economy 175/50 R15 rear and 175/55 R15 front which made the car swinging lighter [ligther steering wheel action and whole vechicle lighter mobility].
I engineered it due to the long gear changes [my gearbox is manual].
With bigger [brand numbers'] tyres I couldn't change to the next gear earlier:
3rd could propel the car only from 50km/h upward
4th could propel the car only from 70 km/h upward
so I had to ride the vechicle with 2nd gear in curved streets
and ride 3rd in long lines..
very reeeving.. not pleasant.
Big torque - yes, but what it was for in easy driving?
so.. the the solution was not m'em bigger, but smaller
to make next gear go earlier.
tyre calculator was my friend and workshop guys were
openly distrustful and unwilling to confide what am doing [and cooperate also ].
And now:
3rd can propel the car from 40km/h
4th can propel the car from 60 km/h
Have I modified the gearbox?
in functionnal manner - yes i have modified the transmission factor.
I have not increased the revs, i've leaped them down.
> It's worth doing if you don't need higher speeds. BTW, is your transmission a 4- or 5-speed? Have you found any information on other forums about swapping the gearbox for one with more gears and/or better gear ratios?
Lazyiness is another factor [LF] in my FE equation - box swap has big LF in FE, so runs uneco-friendly on extreme margins.
But LF has big impact on Velocity Increase [LFoVI], but in negative value! LF big, V small FE fair.
So LF helps LFoVD [LFoV Decrease] and FEI.