Title: Openai/69164192-59d4-800d-8de7-7f4d9033b7f1 - freem URL Source: https://freemwiki.com/index.php?oldid=593145&title=Openai%2F69164192-59d4-800d-8de7-7f4d9033b7f1 Markdown Content: (diff) ← Older revision | Latest revision (diff) | Newer revision → (diff) _This conversation was exported from ChatGPT_[[1]](https://freemwiki.com/index.php?oldid=593145&title=Openai%2F69164192-59d4-800d-8de7-7f4d9033b7f1#cite_note-1) ## gpt-5-1[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=1 "Edit section: gpt-5-1") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=1 "Edit section's source code: gpt-5-1")] ### User: explain why new diesel light duty diesel trucks needs automatic transmissions to pass emmisions[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=2 "Edit section: User: explain why new diesel light duty diesel trucks needs automatic transmissions to pass emmisions") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=2 "Edit section's source code: User: explain why new diesel light duty diesel trucks needs automatic transmissions to pass emmisions")] explain why new diesel light duty diesel trucks needs automatic transmissions to pass emmisions ### Assistant: Here’s the real, engineering-based reason new light-duty diesel trucks must use automatic transmissions to meet modern …[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=3 "Edit section: Assistant: Here’s the real, engineering-based reason new light-duty diesel trucks must use automatic transmissions to meet modern …") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=3 "Edit section's source code: Assistant: Here’s the real, engineering-based reason new light-duty diesel trucks must use automatic transmissions to meet modern …")] Here’s the real, engineering-based reason new light-duty diesel trucks must use automatic transmissions to meet modern emissions laws. It’s not because manuals are “illegal,” but because manuals physically can’t control engine load precisely enough to pass today’s EPA and CARB requirements. ### Modern emission standards for diesels—especially NOx, PM (soot), and cold-start emissions—require extremely tight and predictable control of:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=4 "Edit section: Modern emission standards for diesels—especially NOx, PM (soot), and cold-start emissions—require extremely tight and predictable control of:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=4 "Edit section's source code: Modern emission standards for diesels—especially NOx, PM (soot), and cold-start emissions—require extremely tight and predictable control of:")] * Engine load * Air-fuel ratio * Turbo boost levels * EGR flow * Aftertreatment temperature (DOC, DPF, SCR) * Regeneration timing * Gear selection & shift timing * Torque output in microseconds A manual transmission breaks all predictability because the driver controls load, RPM, and gear changes. Automatics allow the ECM/TCM to coordinate everything so emissions stay inside the allowed envelope. ### To keep NOx and soot down, the ECM needs to:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=5 "Edit section: To keep NOx and soot down, the ECM needs to:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=5 "Edit section's source code: To keep NOx and soot down, the ECM needs to:")] * Reduce torque before a shift * Control turbo vanes * Manage EGR flow * Limit fueling spike * Avoid overboost/underboost With a manual, the shift is uncontrolled and happens at random RPM/load. With an automatic, the ECM and TCM coordinate the shift: * Torque converter locks/unlocks smoothly * Turbo stays spooled * EGR flow stays stable * No smoke spike This alone makes automatics far cleaner. ### DPFs and SCR systems need to stay within specific temperature windows.[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=6 "Edit section: DPFs and SCR systems need to stay within specific temperature windows.") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=6 "Edit section's source code: DPFs and SCR systems need to stay within specific temperature windows.")] Manual transmissions cause: * Lugging → low exhaust temps → incomplete combustion → soot * High-RPM downshifts → temp spikes → NOx surge * Gear mismatch → SCR ammonia slip or under-dosage * Extra soot that overloads the DPF An automatic keeps the engine in the exact RPM/load zone needed for clean burn and proper aftertreatment temperatures. ### EPA 2010+ diesel calibrations use:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=7 "Edit section: EPA 2010+ diesel calibrations use:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=7 "Edit section's source code: EPA 2010+ diesel calibrations use:")] * EGR-on shift * EGR-off shift * transient EGR maps * temperature-dependent intake throttling * VGT coordination during torque management Automatics can precisely execute these strategies. Manual drivers cannot. ### Drivers of manuals sometimes lug their trucks:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=8 "Edit section: Drivers of manuals sometimes lug their trucks:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=8 "Edit section's source code: Drivers of manuals sometimes lug their trucks:")] * 1200–1500 RPM * high load * boosting hard This creates: * Massive NOx spikes * High PM (soot) * Unburnt fuel * Over-reliance on SCR to clean up the mess * Accelerated DPF loading The EPA cycle tests assume optimal load operation. Automatics force the engine into the correct load range. ### The cycles (FTP-75, US06, Cold Start, Low Load Cycle) require:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=9 "Edit section: The cycles (FTP-75, US06, Cold Start, Low Load Cycle) require:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=9 "Edit section's source code: The cycles (FTP-75, US06, Cold Start, Low Load Cycle) require:")] * Identical shift points * Predictable torque output * No sudden RPM dips * No human variability Automatics allow manufacturers to: * Lock shift schedules * Pre-program torque reduction * Pre-program turbo/EGR response * Avoid driver error Manuals cannot meet repeatability → cannot pass. ### The SCR system (DEF injection) works only when:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=10 "Edit section: The SCR system (DEF injection) works only when:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=10 "Edit section's source code: The SCR system (DEF injection) works only when:")] * NOx output is predictable * Exhaust flow is stable * Load doesn’t change violently Manuals create: * transient NOx spikes * unpredictable DEF needs * catalyst out-of-range temps * ammonia slip and under-dosing Automatics keep exhaust flow smooth, which is mandatory for accurate DEF injection. ### Modern diesels run:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=11 "Edit section: Modern diesels run:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=11 "Edit section's source code: Modern diesels run:")] * High cylinder pressures * Piezo or high-pressure solenoid injectors * Tight emissions calibrations During shifts, the ECM must: * Cut fuel * Control injection timing * Prevent torque spikes Manuals make it impossible to coordinate torque management with the shift event. ### Manual diesel trucks died off because:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=12 "Edit section: Manual diesel trucks died off because:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=12 "Edit section's source code: Manual diesel trucks died off because:")] ✔ Ultra-low NOx standards ✔ DPF + SCR + EGR complexity ✔ Transient emissions control ✔ EPA cycle repeatability demands ✔ Aftertreatment temp control ✔ Customer towing expectations (autos tow better) ✔ Automatics eliminate driver-caused emissions spikes Manufacturers could technically design a manual diesel to pass… …but the calibration cost would be enormous, and shift-cycle variability makes certification nearly impossible. ### A manual transmission introduces uncontrolled RPM and load behavior, making modern diesel emissions systems impossible to calibrate and pass certification.[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=13 "Edit section: A manual transmission introduces uncontrolled RPM and load behavior, making modern diesel emissions systems impossible to calibrate and pass certification.") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=13 "Edit section's source code: A manual transmission introduces uncontrolled RPM and load behavior, making modern diesel emissions systems impossible to calibrate and pass certification.")] An automatic transmission: * Controls engine torque * Controls load * Controls shift points * Coordinates with turbo, EGR, and DEF * Maintains aftertreatment temperatures * Keeps combustion clean and predictable Without that control, the diesel simply cannot meet EPA and CARB standards. If you want, I can also create a short version, a Reddit reply, or a "dumbed down" explanation for someone who doesn’t understand modern diesel emissions. ### User: do all new diesel pickups have like 10 gear transmissions[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=14 "Edit section: User: do all new diesel pickups have like 10 gear transmissions") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=14 "Edit section's source code: User: do all new diesel pickups have like 10 gear transmissions")] do all new diesel pickups have like 10 gear transmissions ### Assistant: Short answer:[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=15 "Edit section: Assistant: Short answer:") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=15 "Edit section's source code: Assistant: Short answer:")] Short answer: Yes, basically all new diesel pickups now use 8–10 speed automatics — and 10-speeds are now the dominant standard. Manufacturers moved to high-gear-count transmissions because emissions rules and fuel economy requirements practically force them to. Here’s the breakdown: ### ✅ New Diesel Pickups & Their Transmissions (2024–2025)[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=16 "Edit section: ✅ New Diesel Pickups & Their Transmissions (2024–2025)") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=16 "Edit section's source code: ✅ New Diesel Pickups & Their Transmissions (2024–2025)")] ##### Ford Super Duty (6.7 PowerStroke)[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=17 "Edit section: Ford Super Duty (6.7 PowerStroke)") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=17 "Edit section's source code: Ford Super Duty (6.7 PowerStroke)")] * 10-speed TorqShift (standard on all trims) * No more 6-speed. ##### GM Duramax (2500/3500)[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=18 "Edit section: GM Duramax (2500/3500)") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=18 "Edit section's source code: GM Duramax (2500/3500)")] * 10-speed Allison-branded auto * Replaced the old 6-speed. ##### RAM Cummins (2500/3500)[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=19 "Edit section: RAM Cummins (2500/3500)") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=19 "Edit section's source code: RAM Cummins (2500/3500)")] * 68RFE = 6-speed (in 2500) * Aisin = 6-speed (in 3500 high output) 👉 RAM is the only major holdout still using 6-speeds, but even they are expected to move to an 8- or 10-speed soon because of new EPA/CARB rules. ##### Half-ton diesels (when they existed):[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=20 "Edit section: Half-ton diesels (when they existed):") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=20 "Edit section's source code: Half-ton diesels (when they existed):")] * F-150 PowerStroke → 10-speed * Chevy 3.0 Duramax → 10-speed * RAM EcoDiesel → 8-speed (All discontinued because diesel half-tons became too expensive to certify.) ### 🔥 Why So Many Gears?[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=21 "Edit section: 🔥 Why So Many Gears?") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=21 "Edit section's source code: 🔥 Why So Many Gears?")] More gears = tighter control of: ##### 1. Emissions (NOx + soot)[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=22 "Edit section: 1. Emissions (NOx + soot)") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=22 "Edit section's source code: 1. Emissions (NOx + soot)")] Modern diesels must stay in a very specific RPM and load range to be clean. More gears = the engine never lugs, smokes, or spikes NOx. ##### 2. Aftertreatment temps[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=23 "Edit section: 2. Aftertreatment temps") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=23 "Edit section's source code: 2. Aftertreatment temps")] 10 speeds keep exhaust temps stable for: * DPF regen * SCR efficiency * EGR flow stability ##### 3. MPG & CAFE requirements[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=24 "Edit section: 3. MPG & CAFE requirements") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=24 "Edit section's source code: 3. MPG & CAFE requirements")] Manufacturers get massive efficiency gains by always holding the engine at: * low RPM * high torque * best thermodynamic efficiency point ##### 4. Towing power[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=25 "Edit section: 4. Towing power") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=25 "Edit section's source code: 4. Towing power")] Multiple gears let the engine stay in the exact boost zone needed under load. ### 🚫 Why No Manuals?[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=26 "Edit section: 🚫 Why No Manuals?") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=26 "Edit section's source code: 🚫 Why No Manuals?")] Manual diesels cannot meet modern: * transient emissions * NOx limits * DPF loading requirements * certification cycle repeatability So they are effectively impossible to sell now. ### 📌 Bottom Line[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=27 "Edit section: 📌 Bottom Line") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=27 "Edit section's source code: 📌 Bottom Line")] * Ford & GM → full 10-speed across the diesel lineup * RAM → still 6-speed but not for long * High gear count is now mandatory for emissions compliance and fuel economy * Manuals are dead * 10-speed automatics are the new norm If you want, I can also explain why 10 gears work better for diesels specifically (torque curve, boost control, gear spacing, etc.) or compare Ford vs GM vs Ram transmissions. ## References[[edit](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&veaction=edit§ion=28 "Edit section: References") | [edit source](https://freemwiki.com/index.php?title=Openai/69164192-59d4-800d-8de7-7f4d9033b7f1&action=edit§ion=28 "Edit section's source code: References")] 1. [↑](https://freemwiki.com/index.php?oldid=593145&title=Openai%2F69164192-59d4-800d-8de7-7f4d9033b7f1#cite_ref-1)["Diesel trucks emissions requirements"](https://chatgpt.com/share/69164192-59d4-800d-8de7-7f4d9033b7f1). ChatGPT. Retrieved 2025-11-14.