Leon FR *mustn't* run on 95 fuel?!?

[Noel<>leoN]

I've had a search but can't find a previous thread on this (hopefully I'm not going to get flamed for missing something obvious now

I got a nearly new leon FR (petrol) about 2 months ago. It was 12 months old but had only done 2900 miles. For the first 2 or 3 weeks, about 1500 miles(I drive a long way for my job), the car was fine, so I was having a great time.

Since then though, I keep getting a warning light on the dashboard about the exhaust quality- something fairly generic. When I take it to the garage (its been 5 times now for the same problem), each time they around with it for a bit and then pronounce it fixed. I then drive it between 20 and 200 miles and the warning light comes back on again. There doesn't seem to be any common theme to when it comes on either.

I have now been told that it won't run on 95 RON fuel, I have to buy superunleaded only. This seems like a load of rubbish- the manual and label inside the filler cap both indicate that although 98 is preferable, 95 should be fine, albeit with "slightly reduced performance". Also, why has it taken 5 visits for them to "remember" this?

When I'm communting on busy roads and motorways I don't want to have to fork out significantly more on 98 fuel when I'm not going to notice the difference (if there is any- cue more flaming )

Has anyone else been told this, and does it sound like a fob off answer to either cover up a design fault or a "we can't be bothered ot look at this problem any more"?

Thanks in advance!

 

[DanGB]

yes, the genreal consenses is, if run on 95, you may lose some performance, buts thats all.

 

[andycupra]

your correct. they are talking rubbish.

 

[phil3012]

I confirmed this with SEAT before I ordered my Cupra and the response was as follows:

"After investigating your query with SEAT UK's Technical Department, I can advise that the SEAT Leon Cupra can be run on 95 octane fuel, however, you may encounter a slight power loss. Therefore, it is recommended that the vehicle be run on 98 octane fuel. I hope this information is of use to you. "

I rang them to confirm the same applied to the FR.

The inside of my fuel filler cap says 95 RON and out of interest the Golf GTi brochure says 95 RON.

 

[Noel<>leoN]

Damn their eyes! Well I guess I'll have to wait for the inevitable 6th time the light comes on and be prepared to argue my case...

 

[leviathan18]

lol we use 91 and 95 here in venezuela and guess what with 95 isnt an issue almost 10000km with it now and 0 problems (knocks wood)

 

[rpmleon]

Picked up my TFSI FR DSG one week ago today having had a 150 TDi Cupra for the last 3 years. (Gone but not forgotten)

I could go into the reasons for moving back to petrol but that would not give you "positive" input to the reason for your question.

General advice I received is always run my new car on super unleaded. However, that said, the manufacture states that it can be run (with a slight loss of performance) on 95 Ron. Consequently, you should not be getting constant warning lights.

Please note that I have no mechanical knowledge but I am led to understand that the car detects the type of fuel used and any change from the "norm" can result in problems. Consequently, a possible explanation is that the previous owner ran the car permanently on Super Unleaded and the car does not like the change to normal unleaded?

My suggestion maybe a load of bull but it may be a thought!

RPM

 

[Chris_Cupra]

Despite the fact that the book says that it can be run on 95 RON fuel with a slight loss of performance, these engines with direct injection and a high compression ratio (10.3:1) + turbo need as much as better fuel with high RON to work perfectly ...!!!

By the way, can anyone clarify whether the Leon FR and Cupra have the same compression ratios (10.3:1), as the Seat's website (www.seat.com) claims 10.3:1 for both, but the S3, that is assumed to have the same engine with the Cupra, on Audi's website is claimed to run at 9.8:1 ...???
What should someone believe ...???

 

[G!zmond0]

That's bad news

 

[alimck]

Your warning light will have very little to do with the quality of fuel you're putting into the car seeing as the lowest quality you can get in the UK is 95. Chances are the garage are plugging in their diagnostics machine, checking the sensors, seeing everything is ok and then resetting the ECU to remove the fault. If it keeps happening again and again (and if the light disappears after starting and stopping the engine three times) then you most likely have a faulty sensor somewhere that needs to be changed.

In spite of the higher compression ratio, almost any stock turbo car will run fine on 95ron fuel. The equivalent of running your car on 95 and 98ron fuel could probably be compared to having an extra person in the car with you. The difference is that small.