2024 Tacoma

I have a new 2024 4th generation Tacoma with the turbocharged 4 cylinder. I live at high altitude so definitely like the HP. I lost 50 HP with my 2007 Frontier. The 1 question that I have is gearing down with the Auto transmission (first 1 I have ever owned) It does not seem to slow it down much on steep hills. Is it because of the higher RPM and the Turbo spinning because of it?

 

I don't live a high altitude, but I've found that the transmission tends to do a fairly good job of engine braking while going down hills. That is, it tends to more or less hold my current speed when going downhill off throttle by downshifting a gear or two rather than picking up speed.

Regardless, I can say that what you're experiencing has nothing to do with the turbocharger. With the throttle closed, the engine doesn't generate much exhaust flow, so the turbo couldn't spool much. Even if it did, the computer will command the wastegate to open when the throttle is shut, so most of the exhaust gas will bypass the turbine. On top of that, the computer injects no fuel when the engine is on overrun, so it makes no power.

Engine braking is 100% about drivetrain losses via engine pumping losses, and internal friction in the engine and rest of the drivetrain. It might be that this drivetrain isn't particularly lossy.

 

Just the nature of a 4 cylinder. The Turbo is doing nothing when coasting or engine braking. My 5.7 Tundra I hardly ever needed to use the brakes going down hill the with V8.

 

Put the transmission in s and downshift it.

 

Are you running with adaptive cruise control on? Mine does very well with engine braking on downgrades.
If you are talking about low speeds on steep grades, then you do need to manually keep it in lower gears as mentioned above. There's a pass I go through frequently where I'm down in second gear a lot.