GTI fuel rating (95 RON)

[monkeyhanger]

I really can't see improved performance for using RON 98 fuel when the car is optimised for RON 95. If it ran better on RON 98 then VW would be recommending the use of RON 98. Not saying RON 98 will do any harm, it's likely money for nowt though. Shoe on the other foot, running RON 95 on a car rated RON 98 (recommended) will result in slightly reduced functionality (power/economy). I wonder whether VAG has dropped to 95 recommended for newer engines following the misfire issues on the 1.4TSI (twin charge 160PS) leading to cracked piston crowns when using RON 95 (recommended RON 98). VAG seem to be ditching it for the 1.8TSI (turbo only) on cars with enough room under the bonnet to accomodate it (A1, Ibiza and Polo retain the 1.4TSI for the performance models).

[Johnc41]

I really can't see improved performance for using RON 98 fuel when the car is optimised for RON 95. If it ran better on RON 98 then VW would be recommending the use of RON 98. Not saying RON 98 will do any harm, it's likely money for nowt though. Shoe on the other foot, running RON 95 on a car rated RON 98 (recommended) will result in slightly reduced functionality (power/economy). I wonder whether VAG has dropped to 95 recommended for newer engines following the misfire issues on the 1.4TSI (twin charge 160PS) leading to cracked piston crowns when using RON 95 (recommended RON 98). VAG seem to be ditching it for the 1.8TSI (turbo only) on cars with enough room under the bonnet to accomodate it (A1, Ibiza and Polo retain the 1.4TSI for the performance models).

Totally agree

[Jimble]

VW don't recommend using 95ron, it's a minimum requirement....

[Johnc41]

VW don't recommend using 95ron, it's a minimum requirement....


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We'll I am sure they would recommend 98 just like the mk5 if it was better

[Jimble]

So why did they "recommend" 98 for the mk5 then?

[Hawaii-Five-O]

I really can't see improved performance for using RON 98 fuel when the car is optimised for RON 95. If it ran better on RON 98 then VW would be recommending the use of RON 98. Not saying RON 98 will do any harm, it's likely money for nowt though. Shoe on the other foot, running RON 95 on a car rated RON 98 (recommended) will result in slightly reduced functionality (power/economy). I wonder whether VAG has dropped to 95 recommended for newer engines following the misfire issues on the 1.4TSI (twin charge 160PS) leading to cracked piston crowns when using RON 95 (recommended RON 98). VAG seem to be ditching it for the 1.8TSI (turbo only) on cars with enough room under the bonnet to accomodate it (A1, Ibiza and Polo retain the 1.4TSI for the performance models).

I currently run a 1.4 TSI 160PS Turbo/Supercharger engine and it clearly states the use if 95 RON inside the filler cap, not 98 RON as you suggest. I've run it for four year on 95 RON its never misfired once.

[Johnc41]

So why did they "recommend" 98 for the mk5 then?

It was made to run on 98 the mk5, if you look you will see that they changed the new engine in the mk6 to run on Ron 95 as it said on my fuel lid, to save money on pointless 98

[monkeyhanger]

I really can't see improved performance for using RON 98 fuel when the car is optimised for RON 95. If it ran better on RON 98 then VW would be recommending the use of RON 98. Not saying RON 98 will do any harm, it's likely money for nowt though. Shoe on the other foot, running RON 95 on a car rated RON 98 (recommended) will result in slightly reduced functionality (power/economy). I wonder whether VAG has dropped to 95 recommended for newer engines following the misfire issues on the 1.4TSI (twin charge 160PS) leading to cracked piston crowns when using RON 95 (recommended RON 98). VAG seem to be ditching it for the 1.8TSI (turbo only) on cars with enough room under the bonnet to accomodate it (A1, Ibiza and Polo retain the 1.4TSI for the performance models).

I currently run a 1.4 TSI 160PS Turbo/Supercharger engine and it clearly states the use if 95 RON inside the filler cap, not 98 RON as you suggest. I've run it for four year on 95 RON its never misfired once.

That issue mainly affected people who flitted between 95 and 98, and some of them had coilpack issues too. VAG are definitely moving away from the 1.4 twin-charge where it is practical for them to do so (size constraints willing). Not saying they were all bad, or even most, but a higher than normal level of issues with that engine. The same misfiring issues were virtually unseen with the 2.0TSI 200/210PS engine.

[monkeyhanger]

If VW state 95 as a minimum (which they do) but do not recommend 98 in any of their brochure material, then I think it's safe to assume that output, mpg and CO2 figures are based on RON 95 fuel use. If you could get higher output or mpg with the routine use of RON 98, i'd expect VW to be making that clear in their literature (quite prominently), hence i've assumed no benefits of using RON 98 fuel.

[david25]

So why did they "recommend" 98 for the mk5 then?

In the old MK5 brochures said Fuel grade, minimum:

5) Thanks to the knock control, unleaded four star (at least 95 RON) can be used instead of unleaded Super plus. In order
to achieve maximum fuel consumption benefits on the FSI engine, Ultra Low Sulphur Petrol (ULSP) must be used.

However the cap had a big 98 RON label.