Very clear and concise explanation. My bus started to 'buck', miss, et al. My mechanic checked it out and told me to run high octane fuel. You explanation confirms. Thank you for sharing your knowledge. Cheers.

91 all day and night long. Chevron is my first choice, then Shell, and finally Mobil. Great informative video as usual.

Premium fuel all day long! Great explanation of why it’s important. I run 95 minimum, or 98 octane ideally. These may not be available depending on where you are in the world, but always go premium. Thanks Mike!

Mike I run 91 octane fuel in my car and 20w50 oil with a zinc additive and I change my oil every 1000 miles in my 67 I’ve done this for pass 20 years and I drive my 67 as a daily driver

In the 70s and 80s I worked at an airport and before the company’s aircraft flew, part of the preflight we had to drain the petcock valve of any water in the fuel. I would collect this 100 octane fuel and ran it in my bug along with the leaded regular gas. It ran so sweet. I have never heard said that lead gas was for cooling. But I understand what you are referring to. For others just in case, in the early days the engine combustion which heated up the engine would cause the fuel to reach its ignition temperature during compression, the fuel would auto-ignite at the wrong time due to fuel being compressed past its ignition temperature. This would cause loss of power and damage to the engine. So, lead was added to combat fuel being compressed past its ignition temperature (cooling). Lead also reduced engine knocking (pinging), wear and tear on the exhaust valve seats, coating them with lead.

Thank you mike, very helpful info

Exactly the same thing I was told back in 1990 when I bought a 1200cc 40h from car craft in riverside, Ca. Great info. Wish I never sold that car.

Unfortunately, I live in NJ and we can not get non-ethanol gas here. The gas station I go to only has 87, 89, 93. The 93 (premium) is what I put in my 2017 Jetta GLI. I'll give the premium a try in my 74 Super (1600 DP) and see how. it goes.

Our 1500SP had 1641 barrels and pistons fitted by the previous owner. I suspect it has higher compression than stock.. We only use it once or twice a month so paying a bit extra for some 98RON is good peace of mind.

Lead also help protecting heads and valve stems

Are you going to make a video on compression ratios?

Mike whats are your thoughts on 12 volt gen verse 12 volt alternator with internal Reg. ?? have you cover this topic in a video already??

Premium gas and regular oil (not synthetic) for me. Am I correct on the oil? Thanks for the video!

Mike, here in Brazil we just have gasoline with ethanol (27%), regular or premium. Do you think the ethanol mixture could cool the combustion chamber? We already use timming set in 15° to help to burn the 27% of ethanol.

Do i have to adjust the setting on the mixture or change jets on the carburetor when i change the octane on the fuel?

Hi Mike, I am going to start running 91 in my 66 bus. Do you ever or does anyone ad a fuel additive of any kind? Thanks for the help 🤙

Got 3 gallons of 93 octane ok to run? In 1600 vw

In the uk cheap fuel is 95 then high octane fuel is 97 or even 99

91...................you pay for what you get , only those that work on their cars, will understand

Ping and dieseling 87 oct octane boost considered thanks Mike and guys in comments sect...

avgas

Normal 95 octane ( not super 100 octane )

Lead is a lube not a cooler.

Lead is having a cooling effect? I never heard such a thing before. Lead is increasing octane number and is protecting the valves, sealing better. For this engine with a compression ratio of 8:1, the lowest octane number is perfect. Wrong advice! If you use high octane fuel, you'll have problems starting the engine in cold weather. Very bad advice. Amazing is nobody disagree while is a well known piece of knowledge. Premium doesn't mean a better fuel, but a fuel with high octane number. Oil industry was many times criticized for using the name Premium for marketing purposes, making people believing they use a better product for their beloved cars.