95 or 98 petrol - what do you use?

**tigger73** · 18-03-2018, 03:34 PM

Originally Posted by theresanothersteve

Totally agree. However, if I get better MPG (L/100KM) using the 95, I'll use the 95. You might have guessed from the fact I was running V8s and now a Duke the cost of fuel does not concern me. The only proviso is I match or better the minimum fuel requirement...

I've logged my car to look at how much timing retardation the ECU is pulling. I've then had the ECU retuned to operate safely on the fuel I'm running. In this case it's Caltex Vortex98 which in SA is definitely not the same as other 98 octane fuel on the market. Generally the manufacturers will put in a tolerance for poor quality fuel in the ECU, however like I said the ECU can only pull timing so far before you get detonation (typically only around 5 degrees).

**theresanothersteve** · 01-04-2018, 09:10 AM

Originally Posted by tigger73

It will only pull timing so far before you get detonation.

If your car specifies min 95 then I guess it's up to you. To be safe I'd always run on the higher octane fuel.

It's not a question of fuel efficiency and whether you can save 0.01c per km, it's about engine life which could potentially cost $1,000's to repair.

Here's something else...

You'll notice from my signature I also run a Ducati. I switched from 95 to 98 to see if there was any difference. Fuel consumption remained the same.

I began to develop a starting issue. Instead of first pop it was taking at least three attempts to get it going. I spoke to the dealer and he suggested to bring it back and they'll put on the latest computer updates, supposedly one was related to fuel mapping. And yes, others were reporting starting issues.

In the mean time I switched back to 95. And the starting issue disappeared.

The moral? Run the minimum fuel standard from thew owner's manual. Try fuel that exceeds the minimum requirement, but monitor the results. If you don't get better fuel consumption or performance (consumption is easier to measure than performance and as the two are related to engine efficiency is probably a good indicator) go back to the 95.

**Dan_3MPS** · 16-03-2018, 11:19 AM

I use 98, usually BP.

From past experience with my GTI and MPS, BP and Caltex are generally good in Brisbane (same fuel source, BP has extra 'stuff' added). Shell varied. I did try some of the others, the GTI seemed to like the Puma fuel but shortly afterwards the carbon canister and N80 had to be replaced which was possibly related. 7 Eleven/Mobil caused bad detonation. Both the GTI and MPS loved the 100 octane fuel when available (United and old Shell V-Power Racing), they had 5-10% ethanol added to help bump that octane number up.

Our cars will generally use less fuel running 98, so the extra cost at the pump is minimal at the end of the day.

**cameleon72** · 16-03-2018, 04:06 PM

I was testing this long time even since my golf 4 , and defiantly I have find that on older VAG engine BP95 is the best petrol ( no bad smell on like rotten eggs , engine run more quiet and smother . On Tiguan 132 Tsi definitely BP 98 Is best performance /engine run smoothens , clean exhaust no bad smell etc.. ( My garage is underground Building so I can notice this very much).Or if you go Caltex than best to go with Vortex 95 instead 98 .if you go Vortex 98 is not good, Engine idle run faster and and more rough , bad eggs exhaust burning smell . For some reason Vortex95 is better on VAG cars, I think Vortex 98 is to rich compared to BP 98. Shell I never like much as is not constant , result was very depend on Petrol station. I doubt that this with petrol can be manipulated by Petrol Station Owners ,mixing cheap petrol with expensive one when they have chance to do , I don't know how inspection is tough on this kind manipulation

**h100vw** · 01-04-2018, 09:50 AM

We measured ran a MK7R on our dyno, made 155kw atw. Nearly 20kw down on the average we see. Owner fessed up to using 95. He was in to get a stage 1 tune, we had to send him away and run through a few tanks of 98.

Different demographic for sure, but if your ecu advances the timing and makes more power, you need less throttle input for the same progress. Noting fuel consumption around town wont really give you the best look at how the fuel makes a difference.

**Ozsko** · 01-04-2018, 10:41 AM

Originally Posted by h100vw

We measured ran a MK7R on our dyno, made 155kw atw. Nearly 20kw down on the average we see. Owner fessed up to using 95. He was in to get a stage 1 tune, we had to send him away and run through a few tanks of 98.

Different demographic for sure, but if your ecu advances the timing and makes more power, you need less throttle input for the same progress. Noting fuel consumption around town wont really give you the best look at how the fuel makes a difference.

When he brought it back it was up 20kw?

**Pzero** · 02-04-2018, 10:10 PM

Switched from 98 to 95.
Noticed no difference in performance or drive.
Consumption is similar or better.
Sticking with 95.

**adrianb** · 03-04-2018, 08:38 AM

Always run 98 in my FGX XR8 Falcon and in the wife's Tiguan. I prefer BP Ultimate but I couldn't put anything remotely scientific behind why.

**ewok666** · 10-04-2018, 09:54 PM

Originally Posted by adrianb

Always run 98 in my FGX XR8 Falcon and in the wife's Tiguan. I prefer BP Ultimate but I couldn't put anything remotely scientific behind why.

Got a tuned Tiguan so would be stupid to run anything other than BP98. Without the tune any decent 95 souls do the job but who knows. In anticipation of the tune we always filled up with 98. I would never NOT tune a car when the results are that good!