Power reduction on new tank of 98RON fuel?

[zoomerang]

I recently purchased a new Golf 77TSI, and while I was never expecting a 1.2L engine to be particularly gutsy, I was extremely surprised by how much oomph it had.

However the other day I noticed it was feeling significantly less powerful. I had to rev hard just to keep up in traffic, and my fuel consumption according to the MFD went up a fair bit. It could all be in my head, but there did seem to be a noticeable change from one day to the next.

The only differentiating factor was that I filled the tank up for the first time the night before. (Prior to this I was still running on the original tank of fuel from the dealer).

I used Shell V-Power, and my understanding is this should be perfect for this vehicle - however the lack of power makes me wonder if the ECU is compensating for a bad batch of fuel? Is there a possibility that the servo 'watered' it down with some 91RON?

If this is the case, am I at risk of any engine damage, or will the ECU adjust timing to run safely in that situation? Is there any way for me to tell if this is actually the case?

[h100vw]

Are you 100% it was 98. I had to put some 95 in my S3 while driving from Adelaide to Brisbane and there was an immediate drop in performance until refilled with 98 again. This is a chipped S3.

The ECU is designed to cope with one off's like this. My advice would be to use up that fuel as quickly as practical and fill it up again.

Another question, were you stuck in traffic at all after filling up? Crawling through traffic heats up the intercooler creating dull performance until you are out on the open road again.

Gavin

I recently purchased a new Golf 77TSI, and while I was never expecting a 1.2L engine to be particularly gutsy, I was extremely surprised by how much oomph it had.

However the other day I noticed it was feeling significantly less powerful. I had to rev hard just to keep up in traffic, and my fuel consumption according to the MFD went up a fair bit. It could all be in my head, but there did seem to be a noticeable change from one day to the next.

The only differentiating factor was that I filled the tank up for the first time the night before. (Prior to this I was still running on the original tank of fuel from the dealer).

I used Shell V-Power, and my understanding is this should be perfect for this vehicle - however the lack of power makes me wonder if the ECU is compensating for a bad batch of fuel? Is there a possibility that the servo 'watered' it down with some 91RON?

If this is the case, am I at risk of any engine damage, or will the ECU adjust timing to run safely in that situation? Is there any way for me to tell if this is actually the case?

[zoomerang]

I'm fairly sure it was 98 - I even dug the receipt out of the garbage to check how much I paid, and the amount lines up with the price of V-Power that day.

(No major traffic issues. I've taken it on several long drives on open road since then).

Would a 77TSI run badly on 95RON? My understanding is it doesn't need 98, although for only 5c/l more I would generally use it anyway.

[Lucas_R]

Hmm there is a recall on the 77TSI motors at the moment for wastegate issues and turbo issues, as well as a software update. Might want to look into that incase thats the reason for the power loss.

PS - info on the recall came from my brother who works at Skoda.

PPS - is it necessary to run the 77TSI on 98ron fuel? I wouldn't have thought so.

[Ryan_R]

Don't forget performance is also considerably affected by how hot it is outside (air intake temps). On any day where the MDI shows the temperature above 25 C it starts to lose a bit. Sometimes I also find I get a power kick by mixing VPower with BP Ultimate, so you might try topping up with that to confirm if it was fuel-related.

[Digger11]

I am still amazed by the peppiness of the little 1.2.
Common view is to use 98 as it gets the best out of the engine, but you can run 95 if you want to. The extra cost of the 98 is pretty much offset by the better fuel economy, so you might as well run 98.

You might have a bad batch of fuel. Run it right down and then fill up with some 98 from a different servo.

[Mountainman]

However the other day I noticed it was feeling significantly less powerful. I had to rev hard just to keep up in traffic, and my fuel consumption according to the MFD went up a fair bit. It could all be in my head, but there did seem to be a noticeable change from one day to the next.

Your turbo hasn't shat itself like it did on my 90TSI has it? Now that leads to a really obvious power drop!

[zoomerang]

Your turbo hasn't shat itself like it did on my 90TSI has it? Now that leads to a really obvious power drop!

I'm pretty sure I can hear the turbo whine when going up hills - so I believe it's still working.

It's a brand new car so I imagine the previous recall has already been applied to the turbo system. I suspect it's simply a bad batch of fuel that's perhaps not quite up to the RON level it claims to be. (Apparently this is pretty common according to some other forum posts?)

Will fill it up with BP next time and see if that makes a difference. It's also entirely possible it's all in my head