Latest posts
-
Best Gear Ratio for Drag Racing: Cross the Line at Redline
The best gear ratio for drag racing is the one that puts your engine at peak-power RPM just as you cross the finish line — in the gear you’ll finish in, with no extra shift in the last 100 feet. Gear for that, and the car spends the whole quarter in its strongest RPM band.…
-
Motorcycle Power-to-Weight Ratio: Why Bikes Are So Quick
The motorcycle power to weight ratio is the single number that explains why two wheels feel so violent — a typical 1,000cc sportbike with its rider aboard sits around 3 lb per horsepower, a figure most supercars can’t touch. That’s the whole secret: not exotic horsepower, but the near-absence of weight. And it’s why a…
-
How to Improve Your Power-to-Weight Ratio (Power Up, Weight Down)
If you want to know how to improve power to weight ratio, the answer is simpler than the aftermarket industry wants you to believe: you have two levers — add power or remove weight. Here’s the math that surprises most people — a 10% power gain and a 10% weight cut improve the ratio by…
-
What Is a Good Power-to-Weight Ratio? (Cars, Bikes & More)
Wondering what is a good power to weight ratio for your car, truck, or motorcycle? A daily-driven car is in great shape at around 14–18 lb per horsepower (roughly 125–160 hp per tonne) — strong enough for easy merging and overtaking without hurting fuel economy. Sporty cars live at 8–13 lb/hp, supercars at 4.5–6.5, and…
-
Why Is My Speedometer Wrong? Causes and Fixes
Why is my speedometer wrong? The short answer: your speedometer never actually measures speed. It counts how many times the wheels or driveshaft turn and multiplies by the tire size it assumes you have. Change what one rotation is worth — or break anything in that chain of assumptions — and the needle lies. Here…
-
How to Recalibrate Your Speedometer After a Tire or Gear Change
Changed your tires or gears and now the speedometer lies to you? Here’s how to recalibrate speedometer readings the right way: it’s a two-part job — first measure exactly how far off it is, then apply the right correction for your speedometer type. This guide walks through both, with the math checked at every step.…
-
What Is Overdrive? How an Overdrive Gear Lowers RPM
What is overdrive? In short: it is any transmission gear with a ratio below 1:1 — for example 0.70:1 — which means the transmission’s output shaft spins faster than the engine. It has one job: drop your engine RPM at highway speed so you burn less fuel, hear less noise, and wear the engine less.…
-
What Should Your RPM Be at 70 MPH? (And Why It’s High)
Wondering what your RPM at 70 mph should be? For most modern cars, 1,800–2,500 RPM at a steady 70 mph in top gear is normal. Big V8s and diesels sit lower, small high-revving engines and older gearboxes sit higher — and anything persistently above about 3,000 at 70 in top gear deserves a look. Here…
-
How to Calculate Your Car’s Top Speed from Gearing
If you’ve ever wondered how to calculate top speed from gearing alone, here’s the secret most drivers miss: every car has two top speeds. One is pure math: at redline, in top gear, on your exact tire size, the gearing only allows a single speed. The other is physics: air resistance climbs so steeply that…
-
Best Gear Ratio for Off-Road and Rock Crawling
The best gear ratio for off road driving isn’t a single number — it’s a setup matched to your tires, terrain, and transfer case. Short answer: for a dual-purpose rig on 33–35″ tires, 4.56 is the sweet spot; for dedicated rock crawling on 35–37″ tires, go 4.88 or 5.13. But axle gears are only one-third…