Today over my lunch hour I decided to go to the local Advanced Auto Parts place to get some Techron for the Jag. They had a two-for-one sale on the large bottle. Anyway, before I put in the Techron, my trip computer had a 160 miles to empty reading. After I put in the Techron, it read 150 miles to empty. Bloody He!!. I was expecting maybe adding about 5-10 miles instead of losing 10 miles. Maybe it's some weird British thing about more volume equals less mileage.

 

Your car is punishing you for disregarding the owners manual's caution not to use any fuel additives....

I use Techron as well. I think it's great stuff. Several techs have told me over the years, "If you aren't willing to spring for a professional fuel injection cleaning service, Techron is the next best thing."

I just hit that same two-for-one sale at Advance Auto Parts last week. Picked up four 20-ounce bottles for the price of two....

 

LOL

You're just not understanding how it calculates. It can only watch how you've been using gas and then figure the miles. So it'll vary, just as driving conditions do.

 

Yeah, but I lost 10 miles just by putting in the Techron. What have noticed is that the trip computer uses the last fill up mpg as a baseline and figures the range from there. As an example, the ave mpg reads 20 mpg and then I fill up. The range to empty gets calculated to be 300 miles approximately. If I drive on the highway and the ave mpg is 30 mpg, the range to empty gets recalculated to 450 miles approximately. It doesn't seem to be dynamically calculating.

 

You didn't lose any miles! And you've simplified how it works (it's some sort of EWMA I think), but either way you simply didn't lose any miles

EWMA = Exponentially weighted moving average

 

Start your engine and leave it idling for 10 minutes and watch the calculations. It updates on a time basis on some and could just have been re-calculating as you put in your additive.
The calculations on my Jags' computers are different to my sportwagon's calcs - go figure?

 

It's a rough estimate. The car can't see into the future to see how you will drive it so it cannot ever be accurate!

 

This may be true- but our S-types don't seem to need either a professional fuel injection cleaning service or a need for Techron. Could it be that Jag was right with their recommendation?

Last highway trip in mine averaged 7.1L/100km, (33 mpg) over a 180Km distance.

 

If you don't believe that our S-Types will ever need to have their fuel injectors cleaned, you may want to speak with Brutal about the improvement in performance after fuel injector cleanings in various S-Types under his care took place....

 

To have an 'improvement', there first must be degradation of some sort. I have none.

Fuel consumption, as per my post above, is that same as when I first bought the car as is acceleration, starting, idling etc, etc. I've long believed that gas already has sufficient cleaning additives already blended in, no supplements required.

 

Our S-Type also achieves identical mpg and performance today at 70,000 miles compared to what it did when we acquired it at 18,000 miles. But I do not expect that run of good fortune to continue forever. At some point, the fuel injectors will need attention. In the meantime, I'll continue to add a 20-ounce bottle of Techron at every oil & filter change I perform....

I have had previous vehicles, mostly pickup trucks and SUVs, that benefitted greatly from fuel injection cleaning after 80,000 miles or so. Granted, that was with early and mid-90s engine technology. Vastly improved since then....

 

Jon,

If you get any more cars, you'll need one of those car elevators.

Mike

 

Yep, I'm tired of playing driveway shuffle every night depending upon which vehicle needs to be first to leave in the morning. Still planning to sell my wife's 2004 Lexus RX330. She never drives it anymore yet wants to keep it for the few days each winter when snow is on the ground and the AWD is preferred. I think I'll eventually win that battle and it will be outta here....