could just be me, need opinions..MPG

**xchristhompsonx** · 02-15-2011 05:56 PM

hey guys, went on a long drive yesterday and I just felt like my car was guzzling gas..I was driving aprox. 73-75 mph and was running at about 3500 rpm's. is this normal? just felt like my tank was gone in no time..just want your guy's opinion/experiences..thanks a lot

**shadowpr** · 02-15-2011 05:57 PM

driving like that in my 09 will definitely lower my mpg.

**poly_poly-man** · 02-15-2011 06:08 PM

Try doing the mpg calculations. Driving like that will lower your mpg. Do the calculations to see what works and what doesn't, and how bad you're doing.

**metaldahlberg** · 02-15-2011 06:24 PM

Ya. At 3500 rpms you are definitely in boost. Cruising at that speed will reduce mpg a lot. If I want good gas mileage in my 2010 I stay below 3000 rpms

**06scoobyrex** · 02-15-2011 06:25 PM

Were you in 4th or 5th gear?

**d_Ziggy_2000** · 02-15-2011 06:27 PM

See what the ratio of rpm to mph is.. My car runs best on around 65mph or so at around 2800 rpm.. If I get up to 70, I hit about 3k rpm.. However to 75 its like 3500 rpm.. So the difference there is quite substantial..

But that's just my two cents on that.. (more like penny and a half actually)

**djclue8713** · 02-15-2011 07:02 PM

For me, below 3k and I get ~24 mpg. Anything above that, I get 20 sometimes lower if I'm feeling spirited.

Sent from my Evo 4G using Tapatalk

**teflon_jones** · 02-15-2011 07:23 PM

Wow what year is your car?

I never realized a WRX would be at 3500 rpm at that speed. It badly needs an overdrive. Glad I have a 6 speed at 80 I'm at 3000.

**Rambo** · 02-15-2011 08:56 PM

Originally Posted by teflon_jones

Wow what year is your car?

Were you in fourth gear? At 70 mph, my 2003 is right about 2900 rpm. Driving as you described will definitely impact your milage. At freeway speeds, I try to keep my rpms as low as possible. I get around 26 on the freeway, and about 21 around town.

**xchristhompsonx** · 02-15-2011 10:24 PM

don't want to have to quote all of you so I'll just answer them all aha

but it's an 05, and I was definitely in 5th gear. I was surprised myself how high the rpm's were...to stay below 3k I have to be going like 65mph or less..just seemed weird to me, didn't know if anything mechanically could be wrong..or if that's just how it is. guess I'll have to drive like a grandma to save gas :/

**SD_GR** · 02-15-2011 10:52 PM

Do you know the history of the car? The gear ratio does not seem stock.

**MainFrame** · 02-15-2011 10:57 PM

Originally Posted by metaldahlberg

Ya. At 3500 rpms you are definitely in boost. Cruising at that speed will reduce mpg a lot. If I want good gas mileage in my 2010 I stay below 3000 rpms

Only in boost if you're accelerating. You can cruise at 6000 rpms and not be in boost.

But I digress.. I tend to get the best mileage driving ~60mph.

**xchristhompsonx** · 02-15-2011 11:22 PM

Originally Posted by SD_GR

Do you know the history of the car? The gear ratio does not seem stock.

unfortunately I don't :/ how could I figure that out?

**SD_GR** · 02-15-2011 11:39 PM

Post speeds at specific rpm for each gear and ask other members with the same model to compare.

**zax** · 02-16-2011 04:59 AM

Originally Posted by teflon_jones

Wow what year is your car?

I never realized a WRX would be at 3500 rpm at that speed. It badly needs an overdrive. Glad I have a 6 speed at 80 I'm at 3000.

The six speed has closer ratios, but the same final drive and STi 6th and WRX 5th have nearly the same ratio (0.756:1 6MT and 0.738:1 5MT). In short, 80mph in 6th should be the same revs as 80mph in 5th on the WRX.

Originally Posted by MainFrame

Only in boost if you're accelerating. You can cruise at 6000 rpms and not be in boost.

This. Boost depends on load, not RPMs.