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Revs too high

Started by Magyar, 31 March 2024, 07:18 PM

Magyar

Hi I have a mercedes 280 s e and when I drive 110 km/h the rpm is at 4000, this seems too high, why are the revs so high??

Thanks
W116 1975 280 se

Max-NL

Is it a manual transmission, or an automatic transmission?
1971 R107 350 SL
1972 W108 280 SEL 3.5
1975 W116 280 S
1975 W116 450 SEL 6.9 #140
1977 W123 230
1992 W124 230 CE
2001 Ducati Monster S4

rumb

MB has long designed engines that run all day at 4K rpm.  This increases fuel economy as well as stays in power range.  Compared to lazy american cars that run at 1500 rpm this seems odd to those not used to it.


PS put your  car in your signature and then it will always be visible to everyone.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

raueda1

Quote from: Magyar on 31 March 2024, 07:18 PMHi I have a mercedes 280 s e and when I drive 110 km/h the revs are at 40000, this seems too high, why are the revs so high??

Thanks
Unless you have installed a turbine engine I'm guessing you meant 4000 rpm?  Gear ratios are HERE.  You can calculate rpm and speed.  Regardless, as an order of magnitude guess, it sounds like you're in 2nd gear.  Or maybe third.  You'd need to do the math to be exact. 
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

Magyar

Quote from: Max-NL on 01 April 2024, 09:04 AMIs it a manual transmission, or an automatic transmission?
it's an auto 1975 280se
W116 1975 280 se

Randys01


Magyar

Quote from: Randys01 on 02 April 2024, 12:41 AMstuck in 3rd
I thought 1975 280se cars had a 3 speed gear box?
W116 1975 280 se

Randys01

I think you'll find it is a 4 speed box.

Nabstud

Sounds about right, remember that the tachometer isn't 100% accurate. Mine is similar, about 3600rpm. As said above, it was designed like that and will run all day at those revs. When you first drive it it definitely feels like its way too high but you soon get used to it.

The 4-speed box only uses first gear if you manually select it OR you put your foot down to the floor when taking off from standstill. In everyday driving it acts like a 3-speed auto.
1975 280S - Australian delivered