[SE7EN335]

Does anyone feel that with a full tank of fuel, the car feels faster?

Whenever I have less than quarter tank of fuel, the car feels laggier and less powerful. Doesn't even break traction in full throttle at 2nd gear. But then when its at full tank of fuel or above half a tank of fuel, the car feels a lot faster and always breaks traction in 2nd gear at full throttle. I'm running about 7L of E85 on a full tank of 98.

I'm running v8 MHD stage 2+ 98 RON map. I have catless downpipes, ETS intercooler, chargepipe and tial bov.

HPFP replaced to latest revision. LPFP still original from factory.

Car has done about 109k kms.

[e36mmm]

I have felt this on all my bmws. Whenever the cars reach the last quarter i feel 10% less power and anything over the quarter mark car picks up to where it needs to be and not necessarily needing to be full tank of petrol. Felt this in my e30s, e46 and e9xs. I believe its a safety feature. Hard to explain. I'm sure there is a feasible explanation for it.

[scanspeak]

In what way could it be a safety feature?

[Socket]

I have never noticed this personally

[e36mmm]

Originally Posted by scanspeak

In what way could it be a safety feature?

Maybe a safety feature for the fuel pump? Unsure..

[T1M]

Log low pressure fuel and rail pressure and also load target with full and low tanks and you’ll have your answer.

[gmx]

Originally Posted by T1M

Log low pressure fuel and rail pressure and also load target with full and low tanks and you’ll have your answer.

This, then you'll know if you have a pickup/lean issue or the fuel is simply going "off"