Just in case anyone is interested, Shell Gasoline is the STUFF.

Awhile back, I was having problems with Spark Knock on my 97 F259 351. I tried EVERYTHING to fix the problem, and didnt even have any codes but still had the clatter. Well I figured I would just have to live with paying for the Super Unleaded to stop the clattering. Well I one day I put in Shell Regular Gas (Nitrogen Enriched) I dont know what that means, But I can run Regular gas from Shell in my truck and no Clatter and a little better milage. Well it goes alittle farther.

I filled my wifes 05 EXPY 5.4 with the same gas she always used and drove to Orange Tx, getting about 13.5 mpgs, thats what it consistently ran. On the way back, we had to fill up again ( Its about a 4 hour trip) anyway, we filled it up with Shell and the gas mpg's increased to 15.7, that was about 2 weeks ago. Usually after a week of in town driving, it drops a little. Well after 2 weeks of in town driving, it is still getting a consistent 15.6 mpg. Now I ONLY use SHELL gas.

 

In CA, we have RFGII formulation, so brand makes no difference. It's all E10 with a certain vapor pressure and distillation curve. Only the detergents can vary. Maybe in your part of TX, Shell is the only one selling pure gasoline and not ethanol blends. That can make a huge difference in some engines.

This "nitrogen" thing is more hype from a company that has been hyping stuff like this for decades. "With TCP" was the Shell ads that I remember from the 1960's. My uncle was a retired refinery manager and explained that TCP was not a miracle additive, but the same Tri-Catalytic Process that everyone used.

Jim

 

On the goldwing forum
everyone reporting lower mileage with shell nitrogen
same with alcohol blends
anytime you put in something with lower btu's, mileage suffers
if its going to give me 10% less mpg, they need to charge me less

try a couple more tanks and report back

 

First of all, for anyone who doesn't know me, I track gas mileage like it is my job. I consider it to be a hobby but some might call it an obsession. Whichever.

I had been using nothing but Hess gas for about three years - mainly because there is a station real close to my house and they always had slightly less than average prices for my area. About a year and a half or so ago (I'd have to check my records ) I filled up with Shell gas (a couple pennies more but needed it right then) and noticed that my tank average was one mpg or so higher than normal. I kept buying Shell from then on and my gas mileage has consistently been better. The occasional Hess tank seems to knock a little bit off.

That said, I've noticed over the last couple months that my mileage is slightly less than it should be for the temperatures we have been having. The tank I am on now I am running around 36 when normally I'd be at 38 or so for the spring temperatures we are having. The dip in mpg seems to coincide with the new nitrogen enhanced Shell gas. I don't have enough tanks to "prove" anything yet but like was mentioned, any time you add something to a mixture that lowers the BTU's, mileage WILL suffer.

I'm going to keep watching this and see how it goes.....maybe time to go back to the non-nitrogen gas and see what happens.

 

Well we are getting ready to take a trip up to Austin, then Killen, then to Dallas, then to Canton, then back home. I am going to try to use nothing but Shell and see how much the milage changes, good or bad. The wifes EXPY is still showing the 15.6, no change and still nothing but in town driving

 

Its odd that Nitrogen compounds are considered an undesirable contaminant in motor oil, but supposedly a miracle supplement to gasoline. I have a strong sense that the nitrogen is just a small part of the detergent package that Shell is decided to make into a big marketing blitz. I also keep records of every drop of gasoline that goes in every vehicle and calculate the mileage on every tankful. Ive been doing this since 1969, so yes, I am a little nuts. I have never proven a difference among brands.

Jim

 

A little? You need help for that problem.

It's probably impossible outside of a lab to prove anything as far as which gas is better and/or if there is any difference in mileage between brands. But, it seems like (to me) there is a slight increase in my tanks that come from Shell. Way too many variables to ever prove it though.

The Shell nearest me is a couple pennies cheaper than the Hess near me so that is all the justification I need now anyway.

 

When I used to ru a 10.5:1 iron headed 302 on the street and it was real picky on gas. The el-cheapo gas stations 93 octane was not consistent, but usually would ping. Exxon/Mobil/Valero was also inconsistent, Hess didn't cut the mustard either.

I found the best gas to be Sunoco and Shell. When I bought 93 from either of them I never had trouble. They are both honest American companies selling a product with consistent quality. They both typically employ honest fluent english speaking normal Americans, which is a plus in my book. No ghandi's and such that don't speak a lick of english or wish to learn any, and whose legal status may be questionable.

In any event, fuel is not an area to cheap out on. Whenever I build an engine I have a fair amount of money into it. Even a mild build is not "cheap" for me to do. I want my engines to last a long time and give me peak performance and MPG. That means building them to run on 91-93 octane and always purchasing fuel from a place that I know is not lying to me about the octane.

Figure costs in a truck assuming typical ~15 MPG unloaded. Assuming a average $.30 spread from 87 to 93 it costs you $.30 more per mile than running 87, but if your engine is designed to run 87 you would expect to lose 1-2 MPG so the difference changes. In my case of ~5000 miles/year assuming both engines get 15 MPG it costs $100/year more to run 93 octane over 87. Not even worth fretting about. If we take 14 MPG on 87 vs 15 MPG on 93 (likely less difference than actual) we end up burning about 24 gallons more per year. 24 gallons * $2.25 (approx cost of 87) = $54, bringing the increased cost of 93 over 87 down to $46/year. I'll pay that for an extra 20-30 HP, and the more miles I drive the more cost effective it becomes. With enough miles (less than most Americans drive per year) the higher compression engine burning 91-93 octane is cheaper to feed than the lower output 87 octane engine.

 

Since when is Royal Dutch Petroleum (Shell) an "American" company?

I wish I could get 93 octane gasoline here. CARB RFGII E10 with a maximium of 91 AKI is all we Kalifornians are allowed. Brand makes no difference. In the environmentally "bad old days" Chevron and Richfield (now ARCO, owned by British Petroleum), had 104 (research) octane leaded gasoline. That was what my Corvette-engined Impala liked. Sunoco had a similar product in other states.

Higher compression does make an engine more efficient, all other things being equal. So yes, higher octane gas will more than pay for itself when it is required. However, running 91-93 in a low compression engine designed for 87 is a waste of money.

Jim

 

What part of RDS means Americans?
RDS= Royal Dutch Shell.

 

Jeff have you put aftermarket plugs in your truck like splitfires or champions? That is the most common cause of your pinging. Stick with the motorcrafts listed on the sticker under you hood if you have changed them to something else. Nothing fancy. That was the most common reason I found for spark knock before I quit working for Ford.