Blue04

Ok I bought a new federated gold 675CCA June this year. Wasn't happen with and wanted to try a Optima because of the 800CCA/1000. Ya it's double the price of the federated one. Fit fine all good.

Changed all 6 spark plugs to NGK's about 2 weeks ago and noticed the mpg readout went from 15.2 to 15.3 in like a day. 33K from last plug change. 3 of the 6 Champion plugs were junk.

I made a 2 trips yesterday about 8 mi and noticed the mpg went to 15.6??

Then drove 15 mi around 70 mph and watched the mpg go from 15.6 ending at 18.9?? That is highest mpg I have ever seen. Bought it new, now with 93K. Original Starter & Alternator

Did it need to go on the hwy that bad or did the battery cause something weird?

Thanks

alpine.adrenaline

Optima FTW- you're probably getting better spark now with the extra juice and those Champions. More complete burning of fuel. Nice.

Blue04

Well, that's great if all it took was to swap out a Battery. I have a habit of buying parts from a little local auto shop in town. They carry 1 simple line of batteries and always say oh thats plenty of power to start that. Kinda wondered why places like Advance carry Optima's. Do people really buy $180-$220 batteries? I guess so

alpine.adrenaline

Heck yeah, I'm running a yellow top and red top in my XJ, still strong after 3 years.

caged

i have red tops in all my jeeps and a huge yellow top in... my minivan. yep. lol.

dave1123

I really hate to burst your bubble, but a battery is just an electrical storage device. I don't think it has anything to do with fuel mileage. It does help starting and electrical load carrying ability, but I doubt it does anything to make a hotter spark. It's probably the NGKs.

Blue04

All I can say is the the NGK's netted a .1 increase in mpg last month according to the on board computer with the non optima battery. I will be doing a mileage check the next time I fill up. Also, have been running ethanol free fuel. Not anything wild like Shell 93 just 87. Will be back with an update.

XJPat

Those trip computers aren't that exact but it was a combination of both your highway driving and ethanol free fuel.

dave1123

My WJ is running BFG 245/70R16 Rugged Terrain A/T's with 3.55 gearing and a new head with valves and lifters. It's got 178K miles on it and I use 87 octane E10. On a 3 hour run to Rochester and back at 70 mph with all the windows down, I got 20.5 mpg actual, not VIC recorded. That's amazing to me. AND the lock-up converter doesn't work! That's with Champion plugs and a Fram air filter. Normal driving I get around 14-16 mpg.

Of course, in the winter when doing my newspaper route, that goes down to about 12 mpg. That's with lots of idling and 375 stops, u-turns and k-turns. On Sundays I carry about 3/4 ton of paper in it.