I know Larry has explained it before, IIRC, if you have 5 gals of pump 93 and 5 gals of 110, add the two octane numbers and divide by 2 since it 5 gals of each?? I come up with 101.5 octane
Correct. For our uses it's fine to calculate octane of a mixture linearly. Here's more on calculating ratios other than a 1:1 mix as you used for example: https://petroleumservicecompany.com/blog/mixing-fuels-and-calculating-octane/ Devon
Reason im curious is I’m wondering if im maxing out my combo of 11.66 to 1 with only 33* of total timing on my mix of pump 93 and 110??? I don’t want to pound the rod bearings or head gaskets to death.
Your mix sounds good and safe, of course depending on dynamic comp ratio. If aluminum heads, even safer. Devon
here is basically the same formula as Jim has, but using 15 gallons of 89 octane (non-ethanol gas) and 110 race fuel for a 20 gallon tank. 15 x 89 =1335 5 x 110 =550 1335 + 550=1885 1885 / 20=94.25 octane I use this one for just cruising in town on my 8.2.1 dynamic compression motor. A little easier on the wallet for car shows. Fernando
I don’t have an issue buying race gas to mix in with pump premium for as much as it’s driven, but I only have a 5 gallon jug, do you guys have more than 1 race gas jug, or you put it in a 5 gal. thinner can, or something else?
Mark, it helps to have multiple jugs, I have 4 and wish I had one more. Keep your eyes open for garage sales in the neighborhood, sometimes you can catch 5 gallon pales for cheap. The season for mowing just started down here, so going thru a bunch of non-ethanol is easy and having a back up jug helps. Fernando
I have access to plenty of 5 gallon thinner cans, will the gas store well in those? How long does the gas “stay good” for?
This is a great product by VP. 1/2 the cost of 5 gallons of race gas. I’m a little over 10.5:1 with iron heads and this products keeps mine from pinging. Only takes one can for 20 gallons with my setup at 32 degrees all in
Not meaning to open the proverbial can of worms here but it's important to mention that the octane rating of gas back in the 60s and early 70s was stated using a different method than today. In short, the 93 octane high test gas of today is equivalent to the 98-99 octane high test of the past musclecar era as regards to knock protection. Many of us, myself included, with aluminum heads and static compression of 11 to 1 or less can run 93 pump gas without detonation. (as long as dynamic compression is kept at about 8.0 or less. I usually put in 1 gallon of 110 leaded race gas per tank just to make sure. For those wanting/needing to get the same rating as the Sunoco 260 gas of the past (which was 102 octane), The mix of 5 gallons of 110 to 10 gallons of 93 (98.6 oct) from Jim's response would do the trick. A can of the previously mentioned Octanium in the Unleaded version would also do the trick for those with O2 sensors or turbo Buicks.
Years ago, I ordered 2 of these jugs from Amazon, https://www.amazon.com/VP-Racing-Fu...loon+race+fuel+container,automotive,83&sr=1-5 They double shipped me 2 more and didn't charge me. When I brought it to their attention, they said keep the jugs. I gave one to Bruno. I have 3 of them. Every Winter, I buy 15 gallons of Non Ethanol Fuel for Winter storage of my GS. They come in handy for that.
We have a local farm supply store that sells 5gal race jugs for $17 on sale. I’m sure others around the country do the same. I have 10 of them
I have seen those at Tractor supply I just add 5 gal of race gas when I do a fill up has always been good got 30 years now on using that system, must be ok.
