2018 Mercedes-Benz SL-Class Gas Tank Size & Fuel Capacity
Fuel tank capacity
19.8gal · 75 L
The 2018 Mercedes-Benz SL-Class has a fuel tank capacity of 19.8 gallons (75 liters) on every trim.
A full tank is good for roughly 436–554 highway miles or 257–396 miles around town, going by the EPA ratings.
19.8 gal · Bigger than 67% of 2018 models we list.
- By trim
- Gas cap & parts
- Fuel essentials
- Miles per tank
- Fill-up cost
- Other years
- Compared
- Fuel recalls
- FAQ
2018 Mercedes-Benz SL-Class fuel tank capacity by trim
What changes the tank sizeTap an option to filter the table
- Engine
- no difference
All 4 trims
MPG and range are city / highway.
| Trim | Engine | Drive | Tank | MPG city / hwy | Range city / hwy | |
|---|---|---|---|---|---|---|
| SL 450 2dr Convertible 3.0L 6cyl Turbo 9A · RWD MPG 20 / 28Range 396 / 554 mi | 3.0L 6cyl Turbo 9A | RWD | 19.8 gal75 L | 20 / 28 | 396 / 554 mi | |
| SL 550 2dr Convertible 4.7L 8cyl Turbo 9A · RWD MPG 17 / 25Range 337 / 495 mi | 4.7L 8cyl Turbo 9A | RWD | 19.8 gal75 L | 17 / 25 | 337 / 495 mi | |
| SL 63 AMG 2dr Convertible 5.5L 8cyl Turbo 7A · RWD MPG 16 / 25Range 317 / 495 mi | 5.5L 8cyl Turbo 7A | RWD | 19.8 gal75 L | 16 / 25 | 317 / 495 mi | |
| SL 65 AMG 2dr Convertible 6.0L 12cyl Turbo 7A · RWD MPG 13 / 22Range 257 / 436 mi | 6.0L 12cyl Turbo 7A | RWD | 19.8 gal75 L | 13 / 22 | 257 / 436 mi | |
| No trim matches all of these filters. | ||||||
Tank figures are the manufacturer's rated capacity, sorted smallest tank first. Range is tank size times EPA city or highway MPG.
How far a 2018 Mercedes-Benz SL-Class goes on a tank
Gallons left and the distance they cover at each mark on the fuel gauge, at EPA city and highway mileage. At the combined rating of 23 MPG, a full 19.8-gallon tank covers about 455 miles.
| Gauge | Gallons | Highway miles | City miles |
|---|---|---|---|
| Full | 19.8 | 554 | 396 |
| 3/4 | 14.9 | 416 | 297 |
| 1/2 | 9.9 | 277 | 198 |
| 1/4 | 5.0 | 139 | 99 |
| 1/8 | 2.5 | 69 | 50 |
Over 15,000 miles a year (the EPA's yearly estimate) this configuration uses about 652 gallons, roughly 33 full tanks.
Fuel gauges aren't perfectly linear and the low-fuel light comes on with a few gallons still in the tank, so plan your stop before the last eighth.
- EPA combined
- 16–23 MPG
- Tailpipe CO2
- 383–546 g/mi
- EPA greenhouse score
- 2–5 of 10
- Gas guzzler tax
- Yes
- Source
- EPA ratings
What it costs to fill up a 2018 Mercedes-Benz SL-Class
$104.54 to fill the 19.8-gallon tank from empty with premium, at this week's US average of $5.28 a gallon.
| Tank | Fuel | US avg / gal | From empty | From 1/4 tank |
|---|---|---|---|---|
| 19.8 gal | Premium | $5.28 | $104.54 | $78.41 |
By region, 19.8-gallon tank
| Region | Premium / gal | Fill from empty |
|---|---|---|
| East Coast | $4.93 | $97.61 |
| Midwest | $5.37 | $106.33 |
| Gulf CoastLowest | $4.57 | $90.49 |
| Rocky Mountain | $5.12 | $101.38 |
| West Coast | $6.08 | $120.38 |
| CaliforniaHighest | $6.36 | $125.93 |
Prices: U.S. Energy Information Administration retail averages for the week of October 26, 2026. This week's prices by state and city.
Your own price
- 19.8-gallon tank$104.54
- A year of driving (15,000 mi)$3,443
Starts at the US average for premium; type in what your station charges. For other tank sizes, use the fill-up calculator.
SL-Class tank size in other years
The 2018 SL-Class uses the same 19.8 gal tank as every SL-Class since 2013.
| Model year | Tank | Longest highway range |
|---|---|---|
| 2024 SL-Class | 18.5 gal | 500 mi |
| 2023 SL-Class | 18.5 gal | 500 mi |
| 2022 SL-Class | 18.5 gal | 389 mi |
| 2020 SL-Class | 19.8 gal | 554 mi |
| 2019 SL-Class | 19.8 gal | 554 mi |
| 2018 SL-Class | 19.8 gal | 554 mi |
| 2017 SL-Class | 19.8 gal | 554 mi |
| 2016 SL-Class | 19.8 gal | 535 mi |
| 2015 SL-Class | 19.8 gal | 535 mi |
| 2014 SL-Class | 19.8 gal | 495 mi |
| 2013 SL-Class | 19.8 gal | 495 mi |
- 2025
- 2024
- 2023
- 2022
- 2020
- 2019
- 2018
- 2017
- 2016
- 2015
- 2014
- 2013
- 2012
- 2011
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- 1994
2018 Mercedes-Benz SL-Class vs similar 2018 convertibles
The SL-Class has the largest tank of the four 2018 convertibles compared here, 19.8 gallons against 18.5 for the Jaguar F-TYPE.
| 2018 model | Tank | Longest highway range |
|---|---|---|
| Mercedes-Benz SL-Class | 19.8 gal | 554 mi |
| Jaguar F-TYPE | 18.5 gal | 555 mi |
| BMW 4 Series | 15.8 gal | 537 mi |
| Audi S5 | 15.3 gal | 459 mi |
Other 2018 convertibles of a similar size, one model per brand.
2018 Mercedes-Benz SL-Class fuel system recalls
None of the 2 recalls NHTSA lists for the 2018 Mercedes-Benz SL-Class involve the fuel system.
Frequently asked questions
What is the fuel tank capacity of the 2018 Mercedes-Benz SL-Class?
The 2018 Mercedes-Benz SL-Class holds 19.8 gallons (75 liters) on every trim we list.
How many gallons and liters does the 2018 Mercedes-Benz SL-Class gas tank hold?
The 2018 Mercedes-Benz SL-Class tank holds 75 liters, or 19.8 gallons in US gallons.
How far can a 2018 Mercedes-Benz SL-Class go on a full tank?
About 436–554 miles on the highway and 257–396 miles in town, going from full to empty at its EPA ratings. Expect less in practice, since nobody runs the tank dry.
How many miles can a 2018 Mercedes-Benz SL-Class go on a quarter tank?
About 139 highway miles or 99 in town from the 19.8-gallon tank, which has roughly 5.0 gallons left at the quarter mark. Gauges aren't exact, so treat that as a guide.
What gas does the 2018 Mercedes-Benz SL-Class take?
Premium unleaded (required). The label inside the fuel door confirms it for your car.
How much does it cost to fill up a 2018 Mercedes-Benz SL-Class?
At the US average of $5.28 a gallon for premium (EIA, week of October 26, 2026), filling the 19.8-gallon tank from empty costs $104.54. It ranges from $90.49 in the Gulf Coast to $125.93 in California.
How much does a full tank of gas weigh in a 2018 Mercedes-Benz SL-Class?
About 123 pounds for the 19.8-gallon tank. Gasoline weighs roughly 6.2 pounds a gallon.
Does the 2018 Mercedes-Benz SL-Class have a bigger gas tank than the BMW 4 Series?
Yes. The 2018 Mercedes-Benz SL-Class holds up to 19.8 gallons; the 2018 BMW 4 Series holds up to 15.8.
Has the 2018 Mercedes-Benz SL-Class had a fuel pump or fuel system recall?
No. None of the 2 recalls NHTSA lists for the 2018 Mercedes-Benz SL-Class involve the fuel system.
Sources
- Tank sizes: manufacturer-rated capacities from US-market specifications, checked against independent references. Updated October 2026.
- MPG and range: EPA ratings (fueleconomy.gov). Range is tank size times EPA MPG.
- Fuel prices: U.S. Energy Information Administration, week of October 26, 2026 (this week's prices).
- Recalls: NHTSA recall database (Mercedes-Benz fuel system recalls).
Does your owner's manual say something different? Let us know and we'll fix it. More on how we check the numbers.