Petrol vs diesel BMW 1 Series on the used market: which one actually costs less to run today

Shopping for a used BMW 1 Series? Here’s something worth knowing before you start browsing listings: BMW quietly dropped diesel from the 1 Series lineup entirely, so if you want a diesel variant, you’ll have to buy used. To find out what real value looks like across the range, I went through 200+ current listings across all nine variants. Here’s what I found for the 116i, the entry-level petrol model.
Price varies more with mileage than with age in this segment. A newer car with high km can cost less than an older one with low km. I found a 2011 model with 72,000km priced around $8K, a 2013 model with just 10,000km at around $14K, and a 2015 model with 24,000km at around $13K, cheaper than the 2013 despite being two years newer, purely because of the mileage difference. If you’re after the lowest price, an older high-mileage 116i is your best bet; if you want the newest mechanicals for the least wear, the 2015 at $13K looks like the sweet spot here.
Here are the prices for 116i

Model 118d-diesel-engined variants
The 118D is a different story. I could only find 9 listings nationwide, a sign of how scarce the diesel variants have become on the used market. Prices ranged widely: a 2012 model with 76,000km was priced at around $8.5K, while two 2021 models showed a striking gap: $23K for one with 57,891km and $40K for another with just 39,731km. This price gap mainly because of trim, condition and mileage.
Here are the prices for 118d

Model 118i-petrol-engined variants
For the 118i, I checked listings across 14 different model years and found consistent evidence that newer stock commands a real premium in this range. A 2017 model with 44,636km was priced at 13K, and a 2023 model with just 22,000km topped the range at $36K. Unlike the 116i, where mileage swung the price more than age did, the 118i shows a steadier climb; buyers are clearly paying for the newer body shape and updated interior tech as much as for lower kilometres.
Here are the prices for 118i

Model 120d-diesel-engined variants
The 120d is the rarest find in this range. I could only locate three listings nationwide. With low prices and high mileage, the 120d isn’t a sensible daily-driver buy for most people. It’s better suited to buyers looking for a project car or a cheap parts donor, given the age and mileage most examples are carrying, and the known cost of diesel-specific repairs (DPF, injectors, turbo) on cars in this bracket.
Here are the prices for 120d

Model 120i-petrol-engined variants
The 120i has the deepest used-market history of any variant, spanning 13 model years, and it shows a textbook depreciation curve. Values bottomed out around 2007-2009, with low-mileage 2008s selling for as little as $3,950, before climbing steadily through the 2010s to $14,000+ for clean 2016 examples. There’s a notable gap between 2017 and 2023, suggesting this generation wasn’t widely sold new or imported used in NZ during that window. From 2024 onward, prices jump to $38,000-$75,000, but these are essentially new or near-new cars (some with under 50km), not used-market finds. One 2005 listing at $6,990 breaks the curve entirely, priced above cars two to four years newer.  Worth checking before you trust that number.
Here are the prices for the 120i

Model 123d-diesel-engined variant
The 123d is rarer and had a tri-turbo diesel engine, which made it the quickest diesel 1 Series of its time, which kept prices firmer than you’d expect for a 2010 car. I found two listings, both from 2010: one with 187,000km at $7,750, and one with just 88,074km at $15,000. Nearly double the price for less than half the mileage shows buyers are paying a real premium to avoid a high-mileage diesel this old, where injectors and turbos start becoming a worry.
Here is the price for 123d

Model 125i-petrol-engined variant
The 125i’s straight-six petrol engine makes it a bit of an enthusiast pick among the petrol variants. Prices ranged from $10,495 for a 2012 with 117,000km up to $28,000 for a 2019 with 47,506 km, a fairly steady climb with age and mileage, except for one outlier: a 2013 with just 32,253km at $15,995, priced below a 2016 with more mileage. Worth checking service history or accident records on a listing like that before assuming it’s a bargain.
Here are the prices for 125i

Model 128ti-petrol-engined variant
The 128ti is a genuinely rare find on the used market here. I could only turn up one listing, a 2021 with 47,500km at $39,990. That scarcity makes sense given the car’s short production run and its position as a bit of a gap-filler in the lineup, sitting between the standard 128i and the full-fat M135i. One listing isn’t enough to say much about pricing trends, but it does tell you this: if you want a 128ti in NZ, you’ll be waiting for one to show up rather than picking from a shortlist.
Here is the price:

Model 130i-petrol-engined variant
The 130i’s naturally aspirated straight-six makes it another enthusiast favourite, and most listings sit in a tight band regardless of age: $7,000 to $9,980 across 2006-2010 models with mileage between 94,000 and 151,000km. One listing breaks that pattern completely, a 2005 M Sport with 138,900km priced at $16,990, nearly double anything else in the range. If that’s a manual gearbox car, that alone would explain the gap, as the 130i’s 6-speed manual is genuinely sought after; if not, it’s worth double-checking that listing before taking the price at face value.
Here are the prices for 130i

Model 135i-petrol-engined variant
The 135i is the last of the enthusiast petrol range, and prices show it. It’s the only variant in this list where mileage and price track together cleanly across every year, with no real outliers. A 2008 with 129,600km sits at $10,989, up to $16,000 for one with just 71,000km. By 2013, M Sport examples with lower mileage reached $23,980. Part of that is the N54 twin-turbo engine, which has stayed popular with tuners and kept demand steadier than you’d expect for a car this old.
Here are the prices for the 135i