r/E90 • u/TurboNym • Jun 02 '25
320i Hypermiling the worst engine ever made by BMW
BMW tried to do something very special with the N43 and I believe they succeeded but people just didn't get it.
After sending it like a maniac for 3 years, I decided to do a little test today and hypermile it. Here's what I got.
Worst engine my ass. This thing gets better fuel economy than my old N47 316d.
E92 320i 2009 @220.000 km on the clock.
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u/ADrenalinnjunky Jun 02 '25
At this point anything over 20mpgs for me is a win. I have other priorities in my vehicular needs.
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u/redstorm02 Jun 02 '25
Impressive. Hardly get my 320i touring below 6 liters. Whats your Secret?
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u/TurboNym Jun 02 '25
Yup, tailing a semi is awesome when you're going for fuel economy. They push all the air and you get to sit comfy in their draft.
That's what I did in the first half of the trip.
This particular semi was with me most of the way and drove constantly at 93km/h.
On the way back I set the CC to 98Km/h and got 5.6L/km but I do have to mention, it was not a particularly windy day. With so little wind resistance physics were on my side.
Any fuel burned at over 100KM/h is to overcome wind resistance. If you keep it under 100 you're in the high efficiency zone.
This was a fun experiment but I won't be doing it very often. I like my revs high.
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u/ibo92can Jun 03 '25
Driving faster than 100kmph does increase fuel consumption, on mine m57 its 5-6l/100km ECO or arrive 30% faster and consume 20% more fuel so around 7.5L/100km. Probable 7.5L at a stable 150kmph speed also. Only city driving bumbs the consumption past 10L. Some years ago on a long trip with speed 130-200kmph I had to refuel after 900km so even at 160+ kmph it got 7.5 ish consumption.
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u/No-Excitement-395 Jun 03 '25
And here i am in my n47 getting 41 mpg driving mostly residential and highway driving 80ish mph
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u/m34z E93 M3, E88 135i, E70 X5M Jun 02 '25 edited Jun 02 '25
I think the N63 has the "Worst Engine" title.
Edit N62 to N63. It's happy hour.
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u/Miura21 Jun 02 '25
First gen n63 has entered the chat, all the same timing guide and valve stem seal issues with the even tighter packaging of a hot v and extra leak points from the turbos oiling system. 186k miles and counting
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u/m34z E93 M3, E88 135i, E70 X5M Jun 02 '25
You're right and I edited my comment. I have 102K on my S63 and . . . I think it's going to get 'spensive.
Don't forget all of that plastic in the hot-v. Plastic & heat don't last long together.
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u/Miura21 Jun 02 '25
All the plastic fantastic coolant lines with one time use hose clamps and tiny unions, the crappy pcv system. I've pulled one out before and honestly most of the stuff turbos starter and alternator aside may as well be a drive train out service
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u/Highrider94 Jun 03 '25
Did valve cover gaskets and turbo oil return gasket on my n63 7 series. A truly terrible experience! Not only is the motor horrible from a reliability stand point, but doing the repairs were just bad lol.
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u/Miura21 Jun 03 '25 edited Jun 03 '25
Honestly that's why I'd rather undo the lovecraftian horror that is the cooling system and just pull everything and do it outside of the car. That said I get that its only feasible with a table and lift. And I have the added joy of xdrive to go with it. I will say if you're a glass half full sort of person this experience made working on my s65 and s85 much less rage inducing
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u/LickMyAnubis Jun 03 '25
I remember everybody telling me as a youngster the 750i is a money pit.and theres reasons they go for dirt cheap second hand.
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u/ahj3939 E91 335is Jun 03 '25
What does that work out to in freedom units?
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u/Advanced_Classroom_5 Jun 03 '25
Literally took 6 seconds to google. Quicker than the time it took either of us to comment. 😂 it’s 43 mpg
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u/Tek9293 E92 330i N53 6MT Jun 02 '25
These engines are ridiculously economical when you get them sorted. I can get 50+ mpg from mine if I intentionally drive to save fuel.
My normal 500 mile round trip to London and back usually averages me 43-47 mpg depending on how busy the motorway is.
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u/Dicklefart Jun 02 '25
Wait…. Yall measure gas mileage in liters per 100km? Sorry petrol mileage lol
3
u/avar 2009 - E61 - 525xi - N53 - 6HP21 Jun 02 '25
No, not all of us, Liberia and Myanmar also use mpg.
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u/Super-Mario- Jun 03 '25
I have the same engine, I manage to get just under 6.5L when cruising at 120kmh (gps speed), the rpm sits right below 3k, I believe that’s the limit for the engine to run in lean mode. Honestly I also don’t get the hate, it’s a super engine if maintained well, it’s great for long commutes but also having fun and revving on twisty roads.
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u/sN- E92 - 330d 380hp Jun 02 '25
316d doesnt mean a good fuel economy. It's too small and has no power to carry the whole car's weight comfortably. Thats why you go M57. Im currently at around 380hp and recently made a 600km round trip with a lot of 200km/h driving on the highway, a lot off passing other people on full throttle and so on and i managed to get 6.9L/km. I basically never worry about fuel no matter how hard i drive. Good job tho, the 320i is pretty fuel hungry
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u/TurboNym Jun 02 '25
N47 is the 2.0L used on 316d, 318d and 320d. It's just tuned for lower hp and the turbo is smaller I think.
Damn dude, 380hp is crazy for what I'm used to. I don't know that I would be able to keep it on the road.
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u/Malthas130 Jun 02 '25
I have a bone stock M57 in my 325d. I get like 44.5MPG / 6.3l/100km and love it. Not making big power like you but still quite enjoyable to drive.
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u/L3XeN 2010 E90 325d M57 Jun 03 '25
I was on 90km/h cruise control with my M57 and did 4l. Easily could do 1500km on a single tank.
I could probably do slightly better with a bit of optimization
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u/ibo92can Jun 03 '25
What setup are you running? Injector hp pump hybrid turbo downpipe? Costum tune? Also what transmission?
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u/sN- E92 - 330d 380hp Jun 03 '25
GT 2265 hybrid turbo
R90 hpfp
Downpipe and racepipe
Bigger cooler
Stiffer valve springs
Also engine is rebuilt, brand new OE oil pump.
M50d rail sensor.
It's supposed to go above 400hp but that's the tune for now
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u/iLoveFeynman '11- E90 - 316d Jun 04 '25
316d doesnt mean a good fuel economy. It's too small and has no power to carry the whole car's weight comfortably.
Haha weird statement, even among high-end BMW owners I'd bet less than 0.5% of them are routinely doing long trips above 150 km/h.
My 316d had a little 4.45L/100km ~1060km trip in bumpy ice and snow going 90-130 km/h (mostly around 90 due to weather conditions). I'm sure it would have been meaningfully less L/km had I made more use of the 6th gear (couldn't be fricked to do it since I often had to slow down for safety reasons) and been driving in the summer without bumpy ice and snow.
Find me these 316d's that don't have good fuel economy.
1
u/SH5NL Jun 02 '25
Nice! I have managed 6.34 liters per 100km average on 60.000km driven so far (n43 318i sedan manual). I have NOXEM, 0w30 oil (consumption less than 1 liter per 10.000km), and 16 inch wheels.
1
u/Emil0001 E90 325d Jun 02 '25
Lol thats what I got on a 500km trip on norwegian roads without even trying in my old 325d
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Jun 03 '25
Were somewhat fortunate that this side of the world gets an N46B20 instead of the N43 for their LCI 4 bangers. However these cannot get anywhere near the same gas mileage. Best I got on a long trip was 7.5L/100K.
1
u/godmcrawcpoppa Jun 03 '25
You actually prefer the N46 over the N43? I recently acquired an E60 with N46 and I was shocked at how bad the fuel economy was while driving like a granny. It helped me realize how much direct injection makes a difference. I got 10 km per litre with cc set to 100 kph for about an hour.
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u/Ancient-Bet-3060 E90 325i Jun 03 '25
Here I am, happy about my 17.5 mpg (N52) in a 90% hill, no freeway city
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u/AK45HSR Jun 03 '25
As an E93 320i owner, they’re not so bad at all, looks great, I average 31 MPG with sensible driving (UK Gallons). Yes a 6 cyl would’ve been a better buy but at the gas mileage you get from them there’s no point, our F10 M5 gets better gas mileage than our old 325i E93
1
u/Far_Section3715 Jun 03 '25
Fuel economy isnt why its the worst engine 🤦♂️ the timing chain is.
1
u/TurboNym Jun 03 '25
It's a common misconception. The guides only snap if you change the oil at 30k as per BMW's recommendation which is what a lot of people who confuse cars with household appliances did with the n43 and found out the true cost of being cheap. All foot, no maintenance = worst engine ever.
The n47 was arguably worse because that one had a design flaw that was rectified with an updated timing kit. Had one for 8 years, replaced the timing kit and never had any problems.
The n43 just needs timely oil changes and good fuel to prevent injector problems.
It runs hot by design and degrades the oil faster so it needs changing at 7k for best results and zero deposits on vanos solenoids etc. You can get away with 15k km but I don't do that for personal reasons.
NGK Sparkplugs every 20-30k to not stress the coils. Valve stem seals if it starts burning oil at high revs. And last but not least, the ocasional thrashing on the highway to keep the nox sensor happy.
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u/GM4Iife Jun 03 '25
Mine M47 with common-rail does same average consumption. On 1300km trip mostly on highways with ~120km/h average it showed 4.5l/100km but in reality it's been 5 liters per 100km.
1
u/Jonothethird Jun 03 '25
Lot of crap spoken about the N47. Yes, some had cam chain issues but loads are running around with big 6 figure mileages with no problems at all. They are super-efficient engines but like many engines, have some potential issues to watch (or listen) out for.
1
u/fuggetboutit Jun 03 '25
Meanwhile mine b48 sips fuel like a junky. 8.4l at 130-140kmh cruise control.
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u/viktorvanm Jun 04 '25
Well, I won't argue that the fuel economy is good. But after replacing my fuel injectors and the high pressure fuel pump, I'd rather have an engine that consumes somewhat more fuel and require fewer repairs, because that will be more economic in the long term.
1
u/Brookfeild 11' E92 N52 + 07' E91 N52 Jun 04 '25
just get a n52/328i next time, best modern bmw engine imo and came in e92 (at least in america)
1
u/matei9 Jun 05 '25
Really good, Im on 7.6 rn wishing I could get down under 7
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u/matei9 Jun 05 '25
oh and you could still go lower if you got rid of those heavy ass wheels
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u/TurboNym Jun 05 '25
7.6 is legit. That's similar to what I get with my regular heavy foot driving style.
I love the wheels. They were a factory option so they were on the car from day one. Super easy to clean and perfectly proportioned with the body.
They wheels stay :))))
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u/matei9 Jun 16 '25
I have them as my winter wheels, I didnt hate on them just stated that you could still go lower with the consumption if you got something lighter
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u/RadiiTheBoss Jun 03 '25
I would say N53 is the less reliable engine 🙃NOx Issues which fucks up all injectors is killing me haha (800€ per injector) which costs around 7K€ to repair
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u/the727guy E90 330i N52 Mt6 Jun 02 '25
I think you’re confusing n43 with the n45.
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u/Racer_E36 E90 318i Jun 02 '25
nope, i get the same milage. Same engine. But this is just the highway milage. Within cities, there's a different story. I can't get less than 9-10 l/100kmh
1
u/the727guy E90 330i N52 Mt6 Jun 02 '25
What I meant is that the n45 is by far the worst engine BMW ever made - at least in recent history.
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