Introduction. I have noticed that average people don't know basic physics laws, and are unaware that uneven cylinder engines is bullshit. I asked Grok AI to explain why.
Engines with an uneven number of cylinders—like 3 or 5—often get hyped as quirky or innovative, but when it comes to saving gas and technical performance, they’re outmatched by even-cylinder designs (4, 6, or 8). Here’s why.
Balance and Efficiency
Even-cylinder engines, especially inline-4s or V6s, have a natural balance. Their pistons move in pairs, canceling out vibrations. Uneven-cylinder engines, like a 3-cylinder, can’t do this as cleanly. The irregular firing order creates more vibration, requiring extra parts like balance shafts. These add weight and complexity, cutting into fuel savings. A 2018 study by SAE International found 4-cylinder engines consistently outperform 3-cylinders in vibration efficiency by up to 15%.
Power Delivery
Uneven-cylinder engines struggle with smooth power delivery. In a 3-cylinder, for example, there’s a 120-degree gap between firing events, leading to a choppy torque curve. Even-cylinder engines, like a 4-cylinder with 90-degree intervals, deliver power more evenly. This matters for gas mileage: smoother power means less wasted energy. Data from Car and Driver’s 2022 tests showed a 1.5L 4-cylinder Honda Civic averaging 38 MPG, while a 1.0L 3-cylinder Ford Fiesta hit just 34 MPG under similar conditions.
Thermal Efficiency
More cylinders often mean better heat management. Uneven-cylinder engines, with fewer combustion events per cycle, lose more heat through the exhaust. A 2020 report from the Journal of Automotive Engineering noted that 4-cylinder engines achieve up to 5% higher thermal efficiency than 3-cylinders of similar displacement. Less heat loss equals better fuel economy.
Real-World Tradeoffs
Carmakers like Toyota and BMW stick to even-cylinder layouts for their efficiency-focused models (e.g., Prius 4-cylinder hybrids). Uneven-cylinder engines, often found in budget cars like the Mitsubishi Mirage, prioritize cost over performance. The Mirage’s 3-cylinder gets a dismal 36 MPG combined, per EPA 2023 ratings, while a 4-cylinder Corolla hits 41 MPG.
The Verdict
Uneven-cylinder engines might sound cool, but they’re a technical compromise. Extra vibration, irregular power, and heat loss make them worse for saving gas and overall performance compared to their even-cylinder counterparts. Physics laws don’t lie, even beats uneven every time.
[ + ] observation1
[ - ] observation1 4 points 2 monthsApr 10, 2025 01:44:09 ago (+4/-0)
[ + ] i_scream_trucks
[ - ] i_scream_trucks 5 points 2 monthsApr 10, 2025 02:00:30 ago (+5/-0)
[ + ] JudyStroyer
[ - ] JudyStroyer 2 points 2 monthsApr 10, 2025 07:21:44 ago (+2/-0)
Fucking retard pajeet. Or are you going to claim it is “is” like you claimed “touchscreens in cars is” fucking dumbfuck. DunningKrugerologist
[ + ] i_scream_trucks
[ - ] i_scream_trucks 2 points 2 monthsApr 10, 2025 01:57:05 ago (+2/-0)*
Its weird stroke engines i was thinking of.
Most bike engines are single or twins, my vulcan is a v twin and vibrates like fuck over 140kph top gear.
Volkswagen do 3s but a 4 aint shit unless its built like a tank and boosted to the moon (same i4 engines in an 80s bmw road sedan could get 1000-1400hp depending on which f1 designer you talk to)
Volvo does 5s.
6s are the only naturally balanced. Inline simple as fuck but long, vs nice and short but now you need two pistons coupled in the same place therefore weaker linkages and more complicated. V6 on old mans yamaha 650 special was a literal pain in the ass. It vibrated at just the right frequency to make your ass constantly itchy to the point of sheepskin seat covers being an absolute must have.
Everything else lower than 6 needs balancing any more cylinders youre talking more power and specialist engines anyway cost v benefit, zero advantage but massive extra cost and complications for a single piston, pairs easier to add... 12s exist because same balance double power. 10s exist because almost the performance of 12 with lower consumption.... again a motorsport thing, less consumption means either goes further than or needs less fuel (weight and balance gain) than a 12 but complex as fuck. 8s because v8s a decent sized simple block but now you have to fuck with timing and you get either lower power but smoother idle, or higher power and wants to stall after every 8 strokes (idle cop car vs idle dragster)
Somewhere in there plus FIA regulations on F1 (engine capacity and type - ferrari must build x type, put em in their road cars, jaguar etc 'must have it')/Rally (homologation - 'you can race whatever you like, as long as youve sold at least 1000 of them to the public') resulted in what we have.
Rally was the main influence on cheaper compacts and shit Grand Prix more of an influence on the high high end supercars. I6/I8/V6/V8 stuff a whole other beast thats mainly come from the us, us roads on average longer and straighter than europe, Aus similar to US so we ended up with the 6s and 8s being most popular.
Also - trying to build race cars with wwii aircraft engines - v12s worked the best for aircraft think rolls royce merlin (every fucking thing british plus a few tanks and boats) and bmw or daimler benz
(Messerschmitts usually) - balance vs power vs cost vs complication - plus fuckloads of em still being built post war
[ + ] Drstrangestgov
[ - ] Drstrangestgov 0 points 2 monthsApr 10, 2025 07:26:42 ago (+0/-0)