Can Gearing Make Your Car Faster? With Proof! 

I love how you clear up commonly asked car questions with the math as opposed to giving a biased opinion based on your personal car setup. Your explanations makes questioning what to get for my car a much easier process. Appreciate your work!!

I went from 3.73 to 4.181 and it was very noticeable. Top speed gearing went from 185 to like 168 from the math I did, but I can't remember the last time I ever went 185 on the street..

That editing to get the numbers to appear on the whiteboard with a finger snap was really clean. I had to watch that 3 or 4 times

Really appreciate you making these videos man

+5% more g force ---> +5% bigger smile

protip: if your car is slow but you want to feel the g's mount the passenger seat backwards so its facing the rear and sit in it while having your friend slam on the breaks at like 60mph.

So glad you made this video. I changed the final drive on my R34GTR from 3.45 to 4.11 and I'm really pleased with the results. Sadly I did not even think of getting any timings of the acceleration difference but I was certain the car felt a bit quicker, now I can rest knowing that it is quicker :D

We used to run a 3.89 cruisin gear, (1970 Mustang) then bump to the 4.56 on track day ;-) That 351 cleveland engine HATED the 4.56 on the highway !!! And you could hear the carb's secondaries open, which meant your gas gauge would drop quite quickly... The early 80's seem like a century ago... Love your video's :-)

Where was this video when I was looking for a final drive upgrade? Took me months of reading through forums to get similar info found in this video, haha! Glad to know you finally took this approach! More of these kinds of videos please! More not so popular? ways to make your car better!

This RU-vid channel is a must watch. I deal with whiteboards all day at work and for some reason I can stay awake watching yours. It is amazing seeing the diff. gear ratio on a s2000 compared to my Charger RT. Even though the 0-60 difference is within 1 second, the fact the Charger has 2.6 gears really shows the engineering behind effectively delivering power. Keep making vids dude you're doing a great job.

I'm a brazilian mechanical engineering student and I love your videos, bro! Thanks for sharing your knowledge in a fun and easy way.

Even for a daily driver the 4.44 would work if you live in East Europe, because there aren't many highways around here. Now if you live in the mountains it would also benefit you, because of the curvy mountain roads you can't go too fast and some extra wheel torque would help on the way up.

When I saw the difference in the revs, I kinda wished you went for the 4.77 as well . The 4.4 is an improvement nonetheless

my dad worked at Chevy a little after the oil embargo in 1975. he said that Chevy 350s were sucked of so much power they made only around 160hp, but their torque was still there. he made differentials in the assembly line, and said they put more aggressive gearing to compensate for the engine; a faster top speed in 5th gear and a better acceleration in 1st.

Consistent quality.... one for my favourite channels! Especially since I just bought an AP2... finally! So glad you bought an S2000, I follow regularly. Considering intakes and test pipe among my first upgrades for mine, which is bone stock.

One of the reasons I keep watching these videos is your ability to outline and account for as many testing variables as possible in these types of evaluations.

You are my favorite person on RU-vid. Thank you for all of your awesome content!

Just watched an old video on how speed is affected by gearing! Gear 1 highest torque but low speeds. The difference in video/sound/confidence/ preparation is massive way to go!!

I am a mechanical engineering student , when I watch these videos I feel that I am wasting my time in the university. Where can I learn more ? Any books ? these videos are good but I feel that they don't get to the engineering concepts and are very simplified .

I learned how to mess around with final drives and their effect on acceleration in drag racing games as a preteen. Shorter gearing is fun for spirited city driving and fast acceleration bursts, this is why Evos and STIs with their rally style gearing seem to go really hard with only around 200whp, they lose out pretty badly on top speed.

Great video! I went from a 5 speed and a 4.3:1 final drive to a 6 speed with a 3.9:1 final drive on my MR2. It's my daily, lots of highway, and it dropped my revs at 70 MPH from 3500 to 2800. Great for a car with no sound deadening, and 37 MPG is nice too. I did lose some acceleration but gained an LSD.

Great video. I have a 2002 Q45. It came stock with a 2.76 differential. In 2003 they made a few performance improvements, one of which was changing the differential to 3.13. I'm considering swapping it out to the 3.13. This video shed some light!!

I've been thinking about changing the final drive in my Evo. But opposite, I need longer gears now that I'm making 500 HP. Wish I could rev to 9k RPMs though.

lol "what's fun for humans..."

One of the first things I did to the 1963 C10 I’m building was rebuild the 60 year old 3.08:1 open diff to a 3.73:1 posi. Can’t wait to feel the grunt of those lower gears!

That has to be the most efficient and well presented analysis I have seen!! Thank you keep up the great work!

I see why the Spoon chose the 4.44 gear ratio and 1.75 way LSD on AP1/2. Thanks for the informative and systematic explanation.

I could never get tired of watching your videos. It's so awesome that you can explain something like this so we can all understand it clearly. Thank you for all your work, and keep it up with the awesome videos, Jason.

The finger snap and numbers appear bit is classy. Well done. You have arrived! :-)

I was severely geeking out on this while train commuting this morning. Very well done.

I put 4.88 gears in my truck over 4.10 factory. Mostly to correct for larger tires though. It was a huge help and made it a ton of fun to drive when paired with a supercharger.

Whoa! That finger snap magic!

i was just here for the proof for gearing but apparently magic also exists

singlehandedly the best RU-vid channel. perfectly explained should be the name. You make learning/teaching fun! thanks EE!

Oh man almost cried a bit when I saw you plug in those numbers at 4:33. Remember watching your very early videos, I'd always skip ahead when you're filling a giant chart manually lol. Great video as always💪💪💪

more top speed = less acceleration more acceleration = less top speed simple

Jason, this is like the first technical video that actually kinda made sense to me. Kudos :D

I did similar runs back in the day when I ran the 1/4 mile, only my constant was distance, not speed. I ran the 1/4 mile in 13.32 seconds at 112 mph with a 3.90:1 gear ratio. Changing to 4.11:1 gear ratio had me going 12.96 seconds, but I actually went slower, at 108 mph. So I got to the end of the 1/4 quicker, but not faster. Try explaining that phenomenon to people and their heads turn sideways.

I went from 3.21 to 3.92 gears in my pickup truck and also went from a 33inch tire to a 30inch sport tire. Holy crap! With the 8-speed transmission the Hemi can't even tell it's pushing a truck around. Not counting forced induction, it made the biggest performance gain I've ever felt.

my friend and i did this in my car the other day for testing purposes as i am getting my Z tuned soon. the results were surprisingly good. i wrnt from 10 to 60 in about 6.5 seconds with all-season Michelin tires.. i know from experiance that Z's so not achive WOT until you reach 45mph, so it not getting all of the power available. with that being said, im sure after the tune (stickier tires as my TCS went crazy after 35mph) it could do it under 6 seconds easily. good videos brother, keep'm coming.

please explain the beautiful snapping and crackling sounds that rally cars make so well. i start to drool when listening to group b rally cars. o and that noise the turbo makes, not the blow off valve but that odd sputtering sound as if something is slipping. you the man though keep up the dope vids

Wish i had a garage :(

Oh you made it into it's own video! Sorry about my last commenting about that on the install video! Thanks for doing this! :D

With the finger snap and number magic Engineering Explained has finally become The President. Excellent video!

would be interesting to see what the theoretical "fastest" gearing would be or if there is a formula to find it, I once had a car that took 3 gears to 60 and I found that pretty enjoyable to shift more even if it's slower

New subscriber, I’ve watched a few of your videos prior to subscribing. I am an engineer by trade, so your approach to explaining the data is relatable for me. I’m currently in the process of a gear change, I simply used a online calculator to come up with my gear ratio swap, but wanted a deeper understanding so this video was perfect for that. Thank you for taking the time. It does sound like we are similar in that you did the math and second guessed, after the swap you wished you would have went with the smaller gear ratio. We all do those things, but especially “engineers”. 😂

great video. one of my favorite yt channels. great explanations with good supporting facts.

This is exactly what I've been needing to know, have 4.63 in my LSx 240sx and thinking of putting a lower gear in it since im building the motor up.

Engineering Explained creates the perfect blend of car science with car enthusiasm.

I had a 98 Mustang GT, changed from 2:73 gears to 4.10s. Best bang for the buck and in California no worries about smog.

Usually when you answer these I'm only vaguely following, so glad to see you smash a common sense topic that's not really up for debate with the math. If nothing else it gives some solid #'s to stand-on and justify the purchase. Thanks for that.

4:30, that finger snap is the BOMB lol

Great video. I am glad this is being put out there. I remember many Benz V8s with very tall final drives that essentially robbed them of their performance.

You said that from the calculations, you wanted to use the 4.77 instead. You could use slightly-smaller-than-stock rear tire diameter to effectively increase the final drive ratio that little bit more...

How about a variable differential? CVT diff maybe? Best of both worlds.

Thanks for this video - last little push I needed to swap mine out 😆

Good presentation ! I think there's a sweet spot for each car depending on the power/torque curves of the engine and how many gears you have available... ie. you want to remain at peak torque for each upshift since the cars horsepower will determine your top speed. If your car only has 5 or 6 speeds, then a lower ratio diff will definitely improve acceleration with a small increase in fuel consumption. But if you go to the extreme of having too many gears like the 10-speed auto in the new Camaro ZL1, you'll end up being slower around the track than a 6-speed manual, because the gains achieved in keeping the engine rpm high with each gearshift are negated by the time taken for the extra shifts required to reach a certain speed. (if that makes sense) This is why even hypercars today only use 7-speed gearboxes.

4:33 oh you smooth operator

What might be even more fun would be to use very aggressive gearing like the 4.77 but also change the top gear so that it is the same overall gear as stock. That would give you 5 very aggressive gears for playing and for increased g force, but still have your low revving top gear for cruising at highways speeds. That way you have the best of both worlds. Actually with the lower 4.77 final drive, if you shift at the same RPMs as you normally would with the 4.1 final, gas mileage might remain close to the same as stock if you drive not so aggressively. But the main point to a greater reduction final drive is to increase the fun factor. Been there done that.

Great job in analyzing and testing. And proper math done.

it would be nice if you do some 1/4 mile testing times too.. with new tyres vs old, new diff, etc.. what is next? coilovers, exhaust?

I love looking at modifying a car in "smile factor" increase... Thats the way it should be right ? If your a professional driver , thats something else... but 99% of us are not, and never will be... There should be a smile factor index chart ! Great video, as usual...

i wish that changing the final drive on my subaru WRX was that easy.

I agree with what you said - I just wanted to mention that in a real acceleration run (where you change gears the calculations are a bit more complicated. You elegantly avoided that by keeping all the testing in second. You see there is a point that the stock car is using a a lower gear than the car with short gears. At that point the stock car has actually more torque at it's wheels. For example in your S2K between 60-68 mph acceleration the stock car is using 2nd gear while the 4.77 is using 3rd - so the stock car would have an advantage - would that be enough to change the outcome of the race? Probably not but the difference wouldn't be as great for the lower geared car.

Always wanted to try 4.44's, good video! I had Kia Sportage sourced 4.77's in my AP1, it was really fun and felt great on the track but for every day driving at 70mph on the freeway the 4500rpm in 6th got a little old, with my AP2 I decided to keep the stock gearing but always wondered about 4.44's with the improved AP2 transmission.

One thing, that is a good upgrade if you don't want to touch engine parts and make it reach more power but. If you will upgrade your engine and make it get more power and torque you shouldn't throw away that final drive, It depends obviously how much more power would it reach. But in case the engine won for example 100whp you will need it(the 4.1 final drive) more than the shorter one. It's all about what you expect the car do. If you want to drift the 4.77 would be perfect. Another thing. If you want to have almost perfect performance acceleration on each shift you'll have to change individual gears from the gearbox to keep the acceleration always near from the peak of the maximum power whiteout letting revs fall to much. A short experience I had changing my final drive and gears more than 4 times while I was upgrading engine by steps. I started with the original (3.56) after that 3,76 with same engine, then 3,96 with little upgrades, then 3,76 with more upgrades and now I think will return to 3,56 or perhaps 3,37 that is the largest that exist for my car. Hahaha lol. That's only the final drive. From gearbox I changed 3rd and 4ºth gears shorter than original and 1st and 2nd longer with straight teeth gear(I don't know if it's call like that in English sorry LOL) haha well now I have to see the new performance how it is, the curve of hp and torque and see if I have to change some gears again. Well thank your vid, was excellent explained. Regards!

I love how he rides around the floor jack that made me laugh.

Love this info man so extremely helpful but I would love to see all the differences in full with the 4.7 final as well

If you did a Hondata K-Pro ECU mod or even just a flash, that would give you Vtec much sooner and you would love the car even more. It's almost a night and day difference in feel.

great video. I had my stock s2k to 150mph once. it had more to give but I would not say there was much more in it given the road I was on and only having stock power.

Watching you car jack surf at the end was awesome! lol Great addition!

IMO the best solution to get high torque at low rpm and also a high speed at final gear, is to use a gear box with 7,8,9,10 gears. I know everyone knows it.

It's interesting that the attitude toward ambient temperature changes with power. When you said 67F vs 60F I assume that the higher temperatures will give you more traction, thus greatly negate the increase in oxygen. This is probably only valid with enough power to break your tires lose much of the time from 10-60.

Fantastic video as always! I am glad to see your analysis method is the same as what I use. I think you made a good choice with the 4.44s; it should still have the best 0-60 time. I'm jumping from 2.73 to 3.55 myself this summer. Right now, second gear carries me all the way to 85 mph, so I got room to step up the ratio. Should be a lot of fun!

You should do one about maximum acceleration with your car by flooring the throttle, and only use clutch to keep the engine at 8000 RPM. Even when shifting gears, keep the throttle fully open. There will be lots of clutch slip, but you will be lot quicker and g force.

went from. 3.23 to 3.73. 0-60 went down from 5.4 seconds to 4.4 seconds but my top speed is down. I never did a top speed run but there is about a 350 to difference in each gear

Do you remember when TG tried to make an Avantime as fast as an Evo? Remember the massive wheels they had to put on? I bet that's why they went slower. Also I bet that they knew that and just wanted to make a good piece anyways.

The rev limiter will likely have a "soft" limit 200rpm or so before the hard limit at redline. In this range it will progressively start dropping cycles to ease into the limiter.

Top gear is meant for fuel economy on most cars. Top speed will be drag limited rather than gear limited. You might even gain top end by fighting that drag with more torque. I have however seen V8s screw up the launch effectiveness with too low a rear end.

yes changing the tire size is also like modifying gearing....but the acceleration or top speed that you want may not give you a look that you want

Also a great video to explain how RPM is amazing! in this scenario 4.44 wins because you only need to shift once, but with some valvetrain work and cams that could carry the power a bit higher the 4.77 would win if you didnt have to shift till 10,000!

I went from 3.73 to 4.56 in my truck, combined with a slightly larger tire size and it was definanetly noticable. I also didn't lose any highway mpg but gained about a one in the city

In my 5.3L V8, I briefly considered going from a 3.73 to a 4.10 but decided I had enough acceleration and wanted to keep somewhat decent highway mileage. 4.44 and 4.77 sure are some short gears for a street car! Though, obviously, it depends on what the transmission's gear ratios are.

if your changing your tire size the Equation to figure out the Diff Gears is (old ratio*new tire/old tire) so Example of that from my Truck, stock tire size is 245/75/r16, so 245=30.4" Gear ratio=3.73 New tire size 315/75/r16, 315=34.5" (3.73*34.5= 128.85/30.4=4.233) therefor i need to install 4.23 gears which they don't make for my axle so 4.10 gears will work but probable install 4.55 gears to put larger tires in in the future.

Love the video, wish I could have told you before but 4.44 is ideal for an AP2 and 4.77 for AP1 gearing.

Hi EngineeringExplained, Try shifting into 3rd at 7000rpm vs 8300rpm vs redline

I love your videos, miss the STi days but that s2k is clean!!

the 50-60 time doesnt really matter because you rarely ride it out to redline anyway, so the advantages of the more aggressive gears are pretty big in the part of the rev range you spend the most time.

You are the Brian cox of the car world

bruh you read my mind every time. love the way your brains works (yes im also complimenting myself. ill take it. :P ) I too would take the aggressive ratio for more fun in the canyons, though it would be nice to pair this swap with a 6th gear swap (to a smaller 6th gear) to get back some of that highway fuel efficiency, but thats basically the cost of a transmission full rebuild :O

I am running the Integra type R trans on a crx, with a 4.3 diff ratio. The acceleration is amazing but I rev at 4.3k at ~65 mph haha

Differential is not important. It's when the V-tec kicked in yo!

Great video! Always watch it twice in case I missed something! And I seem to understand it better ! Thanks !

Most people doesn't know to change final drive can improve a lot acceleration, I think change FD and LSD can improve your lap time a lot, plz don't supercharger or turbo at first time, it will screw your car, even slower on the race track

ahh bit of a shame you didn't know the results the 4.77 would yeild. great video as always

In other words you tested the thing which is the kindest way to measure the exact upgrade that you did. How about comparing 0-90 or 0-100 mph times with the two FDs? Something with multiple shifts would be much more representative of real world driving. Sure shift times (and exact shift points) would introduce more variance into the test, but that's why you do multiple runs.

A drag race vs stock will be nice

another nice video Jason. I think you should do a live video on Facebook or RU-vid... thay would be cool...

You are starting to add effects. Very well done. How about adding more B-Roll cut aways. It will help your video quality. Thank you.

In an old mercedes, you go with lower gears. People usually put 3.07 on their 300D's (if not from the factory)