W201 2.6 Fuel?

1982-1993 :180E, 190E, 190E 2.3, 190E 2.6, 190D 2.2, 190D 2.5, 190D 2.5 T
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StraightSix
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Model you own: w201
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W201 2.6 Fuel?

Post by StraightSix » Sun 25 Mar, 2018 4:32 am

Hi everyone,

A bit confused about fuel for my 87 190E 2.6. It's a standard Australian market model. The owners manual originally said 98 RON, but there has been an official-looking sticker put over this to change it to 91 RON. Fuel filler just says "UNLEADED".
Does this mean the Australian market cars had their timing adjusted for the lower quality of the fuel at the time? If I run 98 RON should I get the timing adjusted? I like 98 RON because it's cleaner, but can I improve performance as well? Have tried googling and there's posts about changing resistors to adjust timing, so wondering if this was an easy fix?

Thanks,

Andrew
87 W201 190E 2.6
06 VW B6 Passat 2.0 TDI

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Ivanerrol
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Re: W201 2.6 Fuel?

Post by Ivanerrol » Sun 25 Mar, 2018 10:34 am

The timing resistor is the famous R16 plug in.
Many tests have been done to ascertain whether or not changing the R16 value improves engine efficiency or fuel consumption.
The consensus generally being that it only makes a difference a higher revs.

The old leaded fuel available were Standard - 91RON and Super - 98RON.
98 was generally required for higher horsepower engines and Euros.

Most fuel came from relatively ancient Australian refineries. Upgrading these old places required a considerable expense which the oil companies were reluctant to carry out. Most refineries are now closed and the majority of fuel is imported from Swingapore.

The Euro manufacturers made some adjustments for timing so as to use the available unleaded petrol when released.
I.M.H.O. you should use minimum 95 Octane. No Ethanol.

Most later M103 engines model cars with are required to use minimum 95 octane - it's printed in the user manuals.
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

StraightSix
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Joined: Tue 25 Apr, 2017 12:24 am
Model you own: w201
Location: Canberra

Re: W201 2.6 Fuel?

Post by StraightSix » Sun 25 Mar, 2018 1:51 pm

Thank you, very helpful. I wonder why early 2.6s imported here were set to run on 91 RON, and the owners manual amended to reflect this? I guess for more fuelling flexibility in rural areas, perhaps?
87 W201 190E 2.6
06 VW B6 Passat 2.0 TDI

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Ivanerrol
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Re: W201 2.6 Fuel?

Post by Ivanerrol » Sun 25 Mar, 2018 3:36 pm

When the changeover to unleaded occurred the petrol companies were scrambling to Getty higher octane unleaded petrol. The investment cost to upgrade the refineries to produce it was more than the ever expected return. The start of the slippery slope to full reliance on imported fuel.

Did you know that in the event of a major economic crunch or possible war, Australia has only 18 days supply f fuel?
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

StraightSix
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Posts: 14
Joined: Tue 25 Apr, 2017 12:24 am
Model you own: w201
Location: Canberra

Re: W201 2.6 Fuel?

Post by StraightSix » Sun 25 Mar, 2018 5:11 pm

Indeed. Driving my thirsty M103 may become a luxury!
87 W201 190E 2.6
06 VW B6 Passat 2.0 TDI

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AMG
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Re: W201 2.6 Fuel?

Post by AMG » Wed 28 Mar, 2018 8:34 am

98ron.
NO ethanol.

Understand what your fuel is, how it works (chemically) and why ethanol blends in older vehicles will ruin the fuel system.
ethanol is hygroscopic. leaving it in a tank over a long period will cause corrosion and other particulate damage.
ethanol damages seals and orings as those materials were not designed with alcohol-fuels in mind. these will deteriorate, and cause damage to the fuel divider.

the timing not 'that' adjustable. changing the R16 resistor value to the euro spec has no noticeable effect in AU delivered vehicles. the timing maps in the 625 delivered EZL are not as aggressive as people would believe. the resistor value simply determines which timing map to switch to under different operating conditions (TPS, TEMP, rpm) it is a constantly changing input value. there are about 13 timing maps in the EZL. the vehicle uses about 6 of those with the r16 value that is in the vehicle in au-spec. those 6 are at the upper end of the performance 'ignition maps' using the euro map actually changes the high rpm retard and shifts the base maps over one step. It's not a big deal or worth chasing.

The engine is low compression. (9.5:1) and this is where the real power is lost. EU spec models had a 10.5:1 compression, but that too changed over MY updates. So you can see why the R16 change is a waste of time in the 201.029

If power and torque gains are what you are chasing, then find a donor w124 300E / CE / TE and pull the engine, trans, ecu, ezl, klima relay and any other 'spares' you may want (rear subframe, front spindles/hubs/brakes etc. then part out the rest and get some of your $$$ back.

This will net you a 3.0 m103 / 722.3 and a decent increase in low-end torque, no real weight penalty (engines the same, trans is a little heavier - you could still use the 722.409 though) and it's almost a 100% straight bolt-in swap. Just a couple of ancillary swaps between the 201 & 124 parts, but nothing drastic.

If you have a tired engine, this is the quickest way to regain some power.
Current:
1987 560SL 4sp. auto Signalrot "Stella"
1987 190E 2.3-16 5sp. man. Blauschwarz "Hermann"
1992 300CE-24 6sp. man. Perlblau / Iceblau "Gretel"
1992 Range Rover Classic 4sp auto Ardennes Green "Oswald"
2012 E63 AMG Speedshift MCT Diamantweiß "Klaus"
Previous:
1986 560SEL Anthracitgrau "Schultz" - In Mercedes Heaven
1987 190E 2.6 4sp. auto Signalrot "Sabine" - which now resides/owns Andrew M's Garage
1972 350SLC Astralsilber "Lurch" - now in the loving care of Craig B
1989 2.5-16 Blauschwarz 4sp. auto (parted) formerly owned by Derek/Hasan.
2012 Renault Sport Megane RS265 Trophy 8:08 6 sp. man. Liquid Yellow "Jean Rédélé"

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AMG
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Posts: 5788
Joined: Thu 01 Jan, 1970 10:00 am
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Re: W201 2.6 Fuel?

Post by AMG » Wed 28 Mar, 2018 8:39 am

StraightSix wrote:
Sun 25 Mar, 2018 5:11 pm
Indeed. Driving my thirsty M103 may become a luxury!
That should not be the case.

201.029 being driven reasonably hard - the worst I could coax out of it was 13L/100.

Missus used to drive it to work and back and would get 9/100 - and I could never get that.

of note, the 6 speed manual in the m104 coupe is netting me 14-15/100 urban and about 13 on the highway.... not a lot of difference there.

If your m103 is thirsty, then it's clearly needing some servicing, and there will likely be issues with compression, fuel delivery/pressure or possibly the catalyst or EHA on the FD.

are both your temp sensors and wiring functional? (CIS & coolant)
Current:
1987 560SL 4sp. auto Signalrot "Stella"
1987 190E 2.3-16 5sp. man. Blauschwarz "Hermann"
1992 300CE-24 6sp. man. Perlblau / Iceblau "Gretel"
1992 Range Rover Classic 4sp auto Ardennes Green "Oswald"
2012 E63 AMG Speedshift MCT Diamantweiß "Klaus"
Previous:
1986 560SEL Anthracitgrau "Schultz" - In Mercedes Heaven
1987 190E 2.6 4sp. auto Signalrot "Sabine" - which now resides/owns Andrew M's Garage
1972 350SLC Astralsilber "Lurch" - now in the loving care of Craig B
1989 2.5-16 Blauschwarz 4sp. auto (parted) formerly owned by Derek/Hasan.
2012 Renault Sport Megane RS265 Trophy 8:08 6 sp. man. Liquid Yellow "Jean Rédélé"

StraightSix
A Class
Posts: 14
Joined: Tue 25 Apr, 2017 12:24 am
Model you own: w201
Location: Canberra

Re: W201 2.6 Fuel?

Post by StraightSix » Thu 29 Mar, 2018 5:50 am

Thank you both for your knowledgeable posts. I guess my car is not that thirsty, my mileage figures are similar. It's our thirsty car, because the other is a more modern VW diesel, that gets around 6-7 l/100km.
87 W201 190E 2.6
06 VW B6 Passat 2.0 TDI

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